zotero-db/storage/TR8VCDBT/.zotero-ft-cache

(jMDIPARTMENT OF COMMERCE
U. S. COAST AND GEODETIC SURVEY
O. H. TITTlVLAJirN"
SUPERINTENDENT
GEODESY
THE CALIFORMA-WASHINGTON ARC OF PRIMARY TRIANGULATION
BT Comi>utei-, XJ. S. Coast and G-eotietio Survey
SPECIAL PUBLICATION No. 13
WASHINGTON GOVERNMENT PRINTING OFFICE
1913

DEPABTMENT OF COMMERCE
U. S. COAST AND GEODETIC SUKVEY
SUPERINTENDENT
GEODESY
THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION
BY A- L. BA.r.TD'wnsr Computfr, XT. S. Coast and Greodotio Survey
SPECIAL PUBLICATION No. 13
WASHINGTON GOVERNMENT PRINTING OFFICE
lOKi

I<)I3

CONTENTS,
fc*^

Ceierai statement

rTogress of the triangulation : Season of 1903

Season of 1904

Season of 1905

Season of 1906

Methods of observing employed Program of occupation of stations
Stations occupied: Seasonofl903

Season of 1904

Season of 1905

!

Season of 1906

Statement of costs

Statement of adjustments Abstract of horizontal directions and elevations of telescope above the station mark Condition equations Accuracy as indicated by corrections to observed directions
Table of corrections to observed directions

Accuracy as indicated by corrections to angles and closures of triangles
Table of triangles Accord of bases

Accord of azimuths

Twist in triangulation
Explanation of positions, lengths, and azimuths and of the United States Standard Datum
Table of positions

Principal points

Supplementary points Descriptions of stations

Principal points

Supplementary points

Computation, adjustment, and accuracy of the elevations

Thirty-ninth Parallel to Willamette base

,.

Puget Sound to Tacoma base

Willamette base net to Tacoma base

Elevation of Mount Shasta

Accuracy of vertical angle results in the United States Elevations

Table of elevations:

Thirty-ninth Parallel to Willamette base
Willamette base net to Tacoma base

Tacoma base to Puget Sound
Sketches

Index to positions, descriptions, sketches, and elevations

ILLUSTRATIONS.

1. Index map 2. Index map
3. Thirty-ninth Parallel to Bally-Round 4. Bally-Round to Onion-Rust 5. Onion-Rust to Mary-Peterson 6. Mary-Peterson to Davis-Red 7. Davis-Red to Puget Sound

Page. 5

5 6 6
7 7 7

7

8

8

9

9

9

9

15

18

18

19

20

29

30

30

31

33

34

37

42

43

'.

54

57

58

61

62

63

63

64

64 66 67 68 75

68 69 70 71 72 73 74
3

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.
By A. L. Baldwin.
Computer, United States Coast and Geodetic Survey.
GENERAL STATEMENT.
In the spring of 1903 the United States Coast and Geodetic Survey began the reconnoissance for an arc of primary triangulation to extend from the primary triangulation in northern California to Puget Sound. The work of reconnoissance was not done continuously in any one season, but was done a little at a time, in order to interfere as little as possible with the observations. It was usually done slightly in advance of the triangulation, but at times simultaneously with it, and so the two can not be discussed separately. The observing was completed in four summer seasons, beginning in June, 1903, and ending in July, 1906.
The length of the primary triangulation of this arc, along the axis of the scheme, is 577 miles (929 kilometers) and the length of the subsidiary schemes, secondary in character, is about 30 miles (48 kilometers). Fifty-seven stations constitute the main scheme. The mean latitude of the three old stations of the Thirty-ninth Parallel triangulation, from which the arc started, is 39 05', and the northernmost point lies in latitude 47 23'. The triangulation
follows closely the meridian of 122 30'.
The positions and descriptions were prepared for publication by Mr. C. H. Swick. The greater portion of the work of making the difficult least square adjustments was done by Mr. E. H. Bowen and Mr. M. H. Doolittle, the adjustment of the elevations from the vertical measures having been made by the latter. The engineer intent only upon securing the necessary information to enable him to extend his triangulation or to base other surveys upon it will find the information he desires on pages 31-78, commencing with the explanation of the table of positions, lengths, and azimuths. The index printed on pages 75=-78, used in connection with the sketches at the end of the publication, will enable him to find quickly the data for any given locality. There were used to control the lengths in this triangulation the Yolo base in California, the Willamette base, near Eugene, Oreg., and the Tacoma base, near Tacoma, Wash. The Yolo base was measured in 1881 by Assistant George Davidson, who published his report as Appendix No. 8 in the Report of the Coast and Geodetic Survey for 1882. The Willamette and Tacoma bases were measured by the party of Assistant O. B. French in 1906.* During this season of 1906 six primary bases were measured, the other four being a part of the Ninety-eighth Meridian triangulation. Complete measurements were made on each base with 50-meter steel tapes and also with invar tapes of the same length.
PROGRESS OF THE TRIANGULATION.
SEASON or 1903.
Early in 1903 Assistant O. B. French was placed in charge of the field work and in April organized at Eugene, Oreg., a reconnoissance and building party, consisting of a foreman and four men, with a wagon and four horses. With this party Mr. French conducted a recon-
' See Appendix 4, V. S. Coast and Geodetic Survey Report for 1907, " Six primary bases measured with steel and Invar tapes. 5

6

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

noissance through the Willamette Valley to connect with the triangulation of the Columbia
River. By the latter part of May this was so far advanced that the observing could be started
and a party, consisting of Mr. French, a recorder, and four other men, with two wagons and seven horses, started out from Eugene for the first station, Roman, leaving the first party to

build signals. The work was pushed toward the Columbia River as far as the reconnoissance had been completed. Before the end of September both parties returned to Eugene, where a base and its connections with the main scheme were laid out and a part of the stations were

occupied by the middle of October. Throughout the season the signal-building party was

m always

advance of the observing party, erecting signals, cutting lines, opening trails, and

preparing camping grounds. The weather during the whole season was very disagreeable and

uncertain and the cause of much lost time, especially by the observing party, as it was rare

that all the signals to be observed at a station were visible at one time. There were frequent
long intervals of many days when no observations could be made. Between the middle of October and the middle of November Mr. French and the foreman

of the signal party made a reconnoissance southward to connect with the triangulation of the Thirty-ninth Parallel, developing the scheme that with few changes was carried out in 1904.

SEASON OF 1904.

In the season of 1904 the organization of the parties and the method of conducting the work were about the same as in 1903. Assistant J. S. Hill was also assigned to the work, thus enabling Assistant French to devote more time to reconnoissance without delaying the progress of the observing party. The parties were organized in AprU, when some additions were made to the reconnoissance to complete the scheme between the Thirty-ninth Parallel triangulation and the work of the previous season, and a few stations were prepared for obser-
vations. The observing started at Marysville Butte soon after May 1 and the season's work
closed about the middle of November. During this time the whole scheme between the old triangulation of the Thirty-ninth Parallel and the work of the previous season was completed. Between July 9 and August 10 Assistant French made a reconnoissance to connect the work of the Columbia River with that of Puget Sound, which practically settled the scheme of work
for 1905.
Many difficulties were encountered during the season. During April and May snow and
very strong winds greatly delayed the work. At station Soda smoke delayed the party at
one time for six weeks. Many stations were difficult of access. Five stations were reached
by pack trains over distances from 10 to 25 miles and along difficult and dangerous trails. In each of two cases special trails had to be made for a distance of 4 miles and they were so steep that in one case two horses went over backwards and the outfit had to be packed by men. In order to reach station Mears it was necessary to use ladders and hand lines.
SEASON OF 1905.

During the season of 1905 the organization of the parties and method of conducting the work were the same as during the previous season. The field work began about the middle of April
and closed about the middle of October.
The region between the Columbia River and Puget Sound is a very difficult one through which to carry a primary triangulation. Many of the peaks that must be used are flat and heavily timbered and the roads and trails are almost impassable. It is also a region of very bad weather and this fact, together with the prevalence of forest fires, made the delays in observing very great. The scheme that was laid out the preceding season proved to be entirely too expensive, on account of the very high signals required and the great amount of cutting of timber necessary. Further reconnoissance was therefore required and both ])arties took part in it. About June 1 the observing party began work in Oregon, completing the occupation of four stations in the Willamette base net. This party then movel to the vicinity of the Tacoma base and was engaged the rest of the month in signal building. Observing was resumed on July 1.

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

7

In spite of every effort the work connecting the Columbia River triangulation with that of Puget Sound was not completed during this season. Assistant French reported that the weather conditions during this season were the most unpropitious for such work that he had ever
experienced.
At three stations signals over 100 feet high were built, one being 130 feet high. At several stations the instrument was mounted on a high tree. In such cases the tree was guyed with iron wires and a staging was built about the tree. At one station over 200 trees 4 feet or more in diameter and 200 feet high, besides many smaller ones, were cut to open lines. Long and dangerous trails had to be constructed and several accidents happened on them, which fortunately were not serious except to the horses. At the last station the party was caught in the snow and had difficulty in getting out.
SEASON OF 1906.

During this season the work was in charge of Assistant J. S. HiU, who organized a party
on June 11 and finished the last station on July 26, completing the primary' triangulation
between the Columbia River and Puget Sound. He also made the connection between the
primarj' triangulation and the Columbia River work. Between June 18 and July 26 the observing party occupied seven primary stations and incidentally traveled 250 miles by boat, 315 miles by wagon, and 130 miles by trail with pack animals.
METHODS OF OBSERVING EMPLOYED.

The observations for the primary horizontal angles were made in accordance with the General Instructions for Primary Triangulation, as given on pages 170-174 of Appendix 4,
Report for 1911.
AH the horizontal angle measures were made by the direction method, using the 12-inch
(30-centimeter) theodolites made in the Instrument Division of the Survey. These instruments are described in Appendix 8, Report for 1904. The telescope usetl has a clear aperture of 61 millimeters and its focal length is 74 centimeters. The circle is graduated to five-minute spaces and is read by the micrometer microscopes to single seconds.
PROGRAM OF OCCUPATION OF STATIONS.

In the following three tables the primary stations occupied during the several seasons are
arranged in the order of their occupation. The second column of each table intlicates the days on which primary horizontal observations were made, and the third column the number of such days. The letters (az.) after the name of a station indicates that observations for primary astronomic azimuth were made at that station.

Stations occupied. Assistant O. B. French, chief of party and observer.
SEASON OF 1903.
.

Station

THE CALIFOKNIA-WASHINGTON ABC OF PRIMARY TBIANGULATION.
Stations occupied Continued. Assistant O. B. French, chief of party and observer, and Assistant J. S. Hill, observer.
SEASON OF 1804.
' station

THE CALIFOENIA-WASHINGTON ABC OF PRIMARY TKIANGULATION.
Stations occupied Continued. Assistant J. S. Hill, chief of party and observer.
SEASON OF 1906.
station

10

THE CALIF0BNIA-WA8HINGT0N ABC OF PRIMARY TRUNOULATION.

The horizontal directions are reduced to sea level. The correction expressed in seconds is

given by

^h sin2ar cos'<^

p SUl I

where e* =

(o'-6)
,

A = height

of

station

sighted,

= /o the

radius

of

curvature

in

a

plane

normal

to the meridian, <f> = the latitude, and a = the azimuth counted from the south westward.
In the following table are also given the elevations of the telescope of the theodolite above the station mark at each of the primary stations. These elevations enable the reader to judge
of the amount of building done and they permit the engineer or surveyor who uses the stations to form an estimate of the probable amount of building required to make any particular line

clear.

station occupied and elevation

THE CALIFORNIA-WASHINGTON ABC OF PRIMARY TBIANGULATION.

11

Station occupied and elevation

12

THE CALIFORNIA-WASHINGTON ABC OF PRIMABY TRUNGULATION.

Station orcupied and elevation

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

13

Station occupied and elevation

14

THE CALIFORNIA-WASHINGTON ABC OF PKIMABY TBIANGULATION.

.station occupied and elevation

THE CALIFORNIA-WASHINGTON ABC OF PBIMARY TBIANGULATION.

15

station occupied and elevation

16

THE CALIFOBNIA-WASHINGTON ABC OF PBIMABY TBIANGULATION.

Mo.
39. 0-+0.47-(93)4-(96)-(133)+(135)-(136)+(141)
40. 0= -1.79-0 15)+(U7)-(130)+(135)-(136)+(138)
41. 0=-0.14-(123)4-(126)-(131)+(135)-(136)+(139) 42. 0=+0.90-(114)+(115)-(13)+(140)-(142)+(146) 43. 0=+O.62-(93)+(94)-(140)+(141)+(142)-(148) 44. 0=-0.13-?134)4-(135)-(136)+(140)-(142)+(144) 45. 0=-0.36-(122)+(123)-(139)+(W0)-(142)+(147) 46. 0=-1.28-(132)+(134)-(144)+(145)-(150)+(152)
47. 0=-0.22-(137)+(140)-(142)+(145)-(150)+{151)
48. 0=+0.19-(94)+(97)-(145)+(148)-(149)+(150) 49. 0=+1.39-a22)+(124)-(145)+(147)+(150)-(153) 50. 0=-1.70-(106)4-(108)-(118)+(119)-(157)+(158) 51.0= 0.70-(106)+(107)-(156 +(158)-(160)+n61) 52. 0=-0.44-(119)+(120 -(156 +(157)-a59)+(16l) 53. 0= 0.67-(154)+ 156)-(161 +(162)-{172)+(173)
54. 0=+1.01-(154)+(l.55)-(165)+(166)-(17l)+n73)
55. 0=+0.53-(162)+(163)-(164)+(166)-(17l)+(172)
56. 0=-1.51-(166)+a67)-(170)+(17l)-(]81)+(182) 57. 0= 2.00-(169)+(170)+(179)-(182)-(187)+(188) 58. 0=+2.27-(167)+(168)-(174)+(175)-(180)+(181) 59. 0=-0.15-(175)+ 176)-(179)+(180)-(186)+(187) 60. 0=-1.74-(176)+(l78)-(185)+(186)-(189)+(190) 61. 0=+0.03-(176)+(177)-(184)+(186)-(202)+(203) 62. 0=+1.69-(184)+(185)-(190)+(I91)-(201)+(203) 63. 0=-0.30-(183)+(184)-(198H(199)+(200)-(203)
64. 0=+0.08- 191)+(192)-(197)+(198)-(200)+(20l)
65. 0=+1.70-(192)+(193)-(195)+a97)-(208)+(209) 66. 0=+3.20-(192)+(194)-(196)+(197)-(210)+(211) 67. 0=+5.26-(193)+(194)-(207)+(208)-(210)+(212)
68. 0=+1.01-(205)+(207)-(212)+(213)-(221)+(222) 69. 0=-0.82-(204)+(205)+(216)-(222)-(228)+(229) 70. 0=-1.79-(213)+(214)-(2]6)+(22])-(227)+(228) 71. 0=+1.70-(204)+(206)-(223)+(229)-(235)+(237) 72. 0=+5.62-(214)+(215)-(223)+(227)-(234)+(237) 73. 0=+2.22-(216)+(217)-(223)+(228)-(236)+(237) 74. 0=+0.34-(217)+(220)-(233)+(236)-(238)+(240) 75. 0=+1.49-(223)+(226)-(233 +(237)-(239)+(240) 76. 0=+0.11-(219)+(220)-(238)+(241)-(243)+(244) 77. 0=+1.59-(225)+(226)-(239)+(241)-(243)+(245) 78. 0=+1.31-(232)+(233)-(240)+(241)-(243)+(246) 79. 0=+2.11-(218)+(2]9)-(244)+(248)-(250)+(251) 80. 0=+0.H-(224)+(225)-(245)+(248)-(250)+(252) 81. 0=+0.73-(231)+(232)-(246)+(248)-(250)+(253)
82. 0=-0.94-(241)+(242)+(243)-(248)-(249)4-(250)
83. 0=-1.29-(230)+(231)-(253)+(254)-(255)+(258)
84. 0=-0.37-(247)+(248)-(2.50)+(254)-(2r)5) + (257)
85. 0=-1.04-(254)+(255)-(260)+(262)-(263)+(2G4) 86. 0=-0.50-(261)+(262)-(26;j)+(265)-(274)+(275) 87. 0=+0.48-(259)+(260)-(264)+(265)-(274)+(276) 88. 0=+0.69-(2ft5)+(268)-(273)+(274)-(277)+(278) 89. 0=+0.10-(267)+(268)-(277)+(280)-(281)+(282) .
90. 0=+0.37-(272)+(273)-(278)+(280)-(281)+(284) 91. 0=-0.44-(266)+(268)-(277)+(279)-(285)+(286) 92. 0=-0.19-(271)+(273)-(278)+(279)-(285)+(287) 93. 0=+0.01-(269)-l-(271)-(287)+(288)-(291)+(292) 94. 0=-1..53-(269)+(270)-(290)+(292)-(295)+(296) 95. 0=-1.80-(288)+(289)-(290)+(291)-(293)+(296) 96. 0=-0.33-(270)+(272)+(283)-(284)-(294)+(295)+(297)-(298)
97. 0= -641.3+207.1 (10)-254.9 (]9)+3.0 (20)
98. 0=4-6.5+2.83 (l)-2,37 (2)-0.46 (3)+1.15 (ll)-4.40 (12)+3.31 (13)+3.22 (16)-4.99 (17)+1.77 (18) 99. 0=-0.4-0.19 (6)-3.17 (7)+3.36 (8)+2.26 (]3)-4.54 (]4)+2.28 (15)+2.65 (21)-3.77 (22)+1.12 (23)
+ 100. 0= 18.7+2.76 (8)-6.55 (9)+3.79 (]0)-27.80 (31)+1.62 (32)+26.18 (33)+1.85 (40)-43.92 (4n+42.07 (42)
101. 0= -11.6+27.80 (31)-32.36 (.33)+4.56 (34)+1.88 (37)-8.01 (38)+6.13 (39)+43.92 (41)-46.26 (42)+2.34 (43) 102. 0= -2.6+5.32 (35)-6.83 (36)+1.51 (37)-0.19 (43)-4,91 (44)+5.10 (45)+1.28 (53)-1.17 (54)-0.11 (55)
103. 0=-1.4-0.43 (51)-1.92 (.52)+2.35 (53)+2.,33 (58)-7.79 (59)+5.46 (60)+4.65 (66)-4.77 (67)+0.12 (68) 104. 0= -3.8+2.95 (56) -3.40 (57)+0.45 (58)+2.70 (68)-5.58 (69)+2.88 (70) -0.14 (71)-3.09 (72)+3.23 (73) 105. 0= +6.0+2.92 (62)-2.96 (62a)+3.47 (73)-5.50 (74)+2.03 (75)+0.66 (80)-4.85 (80a)+4.19 (81)+0.04 (63) 106. 0=+3.5-4.05 (61)+7.01 (62)-2.96 (62a)-4.85 (80a)+8.29 (81)-3.44 (82)-2.56 (87)+7.68 (88)-5.02 (89) 107. 0=-7.9-4.17 (82)+8.07 (83)-3.90 (84)-1.19 (85)+2.47 (86)-1.28 (87)-0.93 (90)+2.44 (91)-1.51 (92)
-3.49 (103)+6.59 (104) -3.10 (105)
108. 0=-l. 1-0.92 (92)+3.28 (95)-2.36 (98)-3.67 (100)+6.31 (101)-2.64 (103)-1.28 (108)+3.37 (110)-2.09 (HI)
-3.22 (113)+5.23 (116)-2.01 (118) 109. 0=-68.8-0.74 (92) -105.90 (98)+106.64 (9)+12.90 (101)-16.65 (102)+3.75 (103)+53.87 (112)-56.84 (113)
+2.97 (116) 110. 0=+78.7-2.26 (95)+105.90 (98)-103.64 (99)-4.45 (108)+7.66 (109)-3.21 (110)-56.43 (112)+56.74 (113)
-0.31 (118)
111. 0= -228.6-213,7 (95)+216.0 (96)-2.3 (99)-1.0 (121)+7.0 (126)-6.0 (127)+102.2 (129)-3.4 (131)-98.8 (133)
+ 112. 0= 1.3+2.56 (112)-6.23 (117)+3.67 (118)+6.84 (126)-6.01 (127)-0.83 (128)+2.01 (129)+1.35 (130)-3.36 (131)

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

17

No.
113. 0=+10.9+3.24(112)-5.80(115)4-2.56(117)+3.77(130)-3.27(131)-0.50(1.3.5)+2.75(136)-12.68(138)4-9.93(139)
+ 114. 0=+1.3-1.84 (93)4-1.86 (96)-0.02 (98)-6.55 (113)+12.50 (115)-5.95 {117) 1.93 (130)+3.57 (133)-5.50 (135) 115. 0= -319.8+106.34 (94)-108.15 (95)+1.8l (99)+7.10 (121)-10.25 (122)+3.15 (127)+86.15 (143)+3.05 (147)
-89.20 (148)
116. 0=+219-;J-4.07 (114)+7.74 (117)-3.67 (118)+48.20 (129)-1.35 (130)-46.85 (134)-83.65 (143)+85.61 (144) -1.96 (146)
117. 0=-20.3-14.34 (94)+16.23 (96)-1.89 (98)-12.03 (113)+16.10 (114)-4.07 (117)+0.59 (130)+33.70 (133)
34.29 (134)
118. 0=+3.4'+9.87 (112)-25.03 (114)+15.16 (115)+12.48 (122)-8.74 (123)-3.74 (128)+12.68 (138)-17.24 (139)
+4.56 (140)-2.33 (142)-13.16 (146)+15.49 (147)
119. 0=+7.8-2.40 (93)+9.47 (94)-7.07 (97)-2.84 (1371+5.48 (140)-2.64 (141)-8.31 (149)+11.58 (150)-3.27 (151) 120. 0=+26.5+16.23 (94)-29.24 (96)+13.01 (97)+6.27 (132)-39.97 (133)+33.70 (134)+5.84 (144)-2.31 (145)
-3.53 (148)+8.31 (149)-5.97 (150)-2.34 (152) 121. 0=-2.8-5.41 (122)+10.17 (123)-4.76 (124)-7.28 (]37)+10.12 (139)-2.84 (140)+0.79 (142)+2.22 (145)
-3.01 (147)
122. 0= -1.9-4.56 (106)+7.38 (107)-2.82 (108)-0.45 (118)+3.52 (119)-3.07 a20)-1.25 (156)+3.72 (157)-2.47 (158)
-3.53 (159)+4.99 (160)-1.46 (161)
123. 0=+10.6-4.20 (154)+5.94 (155)-1.74 (156)-0.80 (161)+3.29 (162)-2.49 (163)-5.76 (164)+9.22 (165) -3.46 (166)-0.06 (171)+3.22 (172)-3.16 (173)
124. 0=+11.9-1.02 (166)+2.72 (167)-1.70 (168)-2.08 (169)+5.64 (170)-3.56 (171)-3.34 (174)+5.92 (175) -2.58 a76)-2.63 (186)+3.92 (187)-1.29 (188)
125. 0=+10.4-6.63 (176)+9.52 (177)-2.89 (178)-9.47 (184)+10.59 (185)-1.12 (186)-0.30 (189)+18.61 (190)
-18.31 (191)
126. 0=+18.8+4.00 (183)-14.59 (184)+10.59 (185)+18.61 (190)-21.84 (191)+3.23 (192)+0.63 (197)-4.57 (198)
+3.94 (199) 127. 0=-6.8-0.86 (192)+3.11 (193)-2.25 (194)-3.74 (195)+5.87 (196)-2.13 (197)-0.58 (207)+3.25 (208)
-2.67 (209)-4.60 (210)+7.32 (211)-2.72 (212)
128. 0=-21.2+5.36 (204)-4.56 (205)-0.80 (207)+36.00 (212)-44.22 (213)+8.22 (214)+4.04 (227)-53.45 (228)
+49.41 (229) 129. 0=-91.2-5.36 (204)+9.89 (205)-4.53 (206)+0.27 (223)+49.14 (228)-49.41 (229)-79.73 (235)+83.06 (236)
-3.33 (237)
130. 0=+4.6-4.78 (212)+6.59 (214)-1.81 (215)+0.37 (223)+3.65 (227)-4.02 (229)-2.13 (234)+5.28 (235)-3.15 (237) 131. 0=+11.2-1.75 (216)+5.86 (217)-4.11 (220)-3.91 (223)+4.71 (226)-0.80 (228)-0.95 (233)+4.28 (236)-3.33 (237)
-3.18 (238)+4.72 (239)-1.54 (240) 132. 0=-4.1-12.16 (223)+18.46 (225)-6.30 (226)-11.99 (232)+11.28 (233)+0.71 (237)-1.27 (239)+23.50 (240)
-22.23 (241) 133. 0=-22.2-13.89 (217)+20.19 (219)-6.30 (220)-10.77 (232)+11.28 (233)-0.51 (236)+0.09 (238)+23.50 (240)
-23.59 (241) 134. 0=-118.3-401.2 (218)+407.5 (219)-6.3 (220)+0.1 (238)+3.1 (241)-3.2 (242)-3.1 (249)+128.6 (250)
-125.5 (251)
135. 0=-15.2+0.81 (231)-12.09 (232)+11.28 (233)+23.50 (240)-26.66 (241)+3.16 (242)+3.10 (249)-7.16 (250)
+4.06 (253)
136. 0= +287. 5 -164. 9 (223)+178.06 (224)-13.16 (225)-0.81 (231)+0.10 (232)+0.71 (237)-1.14 (245)+1.38 (246)
-0.24 (248) -4.38 (250)+73.49 (252) -69.11 (253)
137. 0= -85.5-3.16 (241)+3.16 (242)+0.85 (243)-7.45 (247)+6.60 (248)-47.27 (249)+47.27 (254)-59.42 (255)
+63.30 (2.56) -3.88 (257)
138. 0=+26.6+0.09 (230)+11.19 (232)-11.28 (233)-23..50 (240)+23.50 (241)+3.49 (243)-3.49 (247)-8.98 (256) +14.88 (257) -5.90 (258)
139. 0=+2.5-5.49 (254)-1.78 (255)-0.52 (259)+2.30 (260)+8.38 (261)-2.89 (262)-0.64 (263)+3.02 (264)-2.38 (265)
-3.75 (274)+6.98 (275)-3.23 (276)
140. 0=-5.0-2.32 (265)+4.54 (267)-2.22 (268)-2.45 (272)+5.49 (273)-3.04 (274)-1.24 (277)+371 (278)-2.47 (280) -2.84 (281)+3.94 (282) -1.10 (284)
141. 0=-3.2-2.77 (265)+4.63 (266)-1.86 (268)-1.86 (271)+4.90 (273)-3.04 (274)-1.24 (277)+4.01 (278)-2.77 (279)
-3.04 (285)+4.28 (286)-1.24 (287)
142. 0=-1.4-2.30 (269)+4.12 (270)-1.82 (271)-2.42 (287)+4.38 (288)-1.96 (289)-1.55 (290)+3.50 (291)-1.95 (292)
-2.28 (293)+5.11 (295) -2.83 (296)
143. 0=-5.7-0.46 (1)+1.42 (3)-0.96 (5)+0.19 (6)-0.21 (8)+0.02 (10)-1.15 (11)+1.15 (13)+2.28 (14) -2.28 (15)
+ +1.77 (17)-1.77 (18)+0.99 (20) 1.12 (21)-1.12 (23)-2.15 (24)+2.15 (25)+3.78 (26)-3.78 (27)-0.56 (29)
+0.56 (30)+5.32 (35) -5.32 (36)+0.42 (37)-0.42 (39)-2.40 (40)+2.40 (41)-0.19 (43)+0.19 (45)-3.58 (46) +3.58 (47) -0.71 (48)+0.71 (.50)+1..53 (51)-1.53 (52)+0.11 (53)-0.11 (.55)+0.45 (56)-1.51 (58)+1.06 (60) +1.08 (61) -1.08 (62a)-1.03 (64)+1.03 (65)-4.77 (66)+4.77 (67)+2.88 (69)-2.88 (70)+0.14 (71)+0.33 (73)
+ -0.^7 (75) -1.81 (80)+1.81 (80a)+1.47 (82)-1.47 (84) 1.19 (8.5)-1.19 (86)-l.ll (87)+l.ll (89)-0.93 (90)
+0.93(91)+1.32(93)-1.32(97)+0.83(100)-1.80(103)+0.97(105)+3.21(109)-5.31(110)+2.10(111)+3.24(121) -2.72 (124)-0.52(127)+2.28 (137)-2.84 (140)+0.56 (141)+0.79 (142)-0.79 (145)-0.75 (149)+0.75 (153) 144. 0=+10.9+1.32 (93)-2.26 (9.5)-1.32 (97)+2.26 (99)-1.14 (106)+1.14 (108)+3.21 (109)-3.21 (110)+0.31 (112) -0.31 (118) -3.07 (119)+3.07 (120)+2.72 (121) -2.72 (124) -0.65 (127)+0.65 (128)+2.28 (137) -2.84 (140) +0.56 (141)+0.79 (142)-0.79 (145)-0.75 (149)+0.75 (153)-0.48 (1.54)+0.48 (156)+2.47 (157)-2.47 (158)
+ +0.14 (159)-0.14 (161)-2.49 (162)+2.49 (163)+1.68 (164)-2.70 (166) 1.02 (167)-2.08 (169)+2.08 (170)
+3.16 (172)-3.16 (173)+2.58 (175)-4.13 (176)+1.55 (178)+0.45 (179)-0.45 (180)+0.18 (181)-0.18 (182) -2.60 (183)+2.60 (185)+1.29 (187)-1.29 (188)+0..54 (189)-0..54 (190)-2.25 (193)+2.25 (194)-0.61 (195)
+ +0.18 (197)+0.43 (199)-2.01 (204)+2.01 (206)+2.67 (208)-2.67 (209) 1.10 (210)-2.91 (212)+1.8l (215)
-4.28 (223)+3.91 (226)+0.37 (229)-0.81 (231)+0.81 (232)+2.13 (234)-2.13 (235)+1.54 (239)-4.16 (240)
+2.62 (242)+0.24 (246)-0.24 (248)+1.14 (249)-1.14 (253)
145. 0=-5..55-(6)+(10)-(ll)+(15)+(18)-(40)+(43a)
146. 0=-5.92+ 4.5a)-(45b)-(46a) + (50)-(66)+(70)-(71)+(75)-(80)+(84)-(90)+(94)
147. 0=-0.10-(94)+(98)-(113)+(120)-(159)+(163)-(164)+(168)-(174)+(178)-(189)+(194)-(210)+(213)+(220)
-(221)-(238)+(242)-(249)+(262)-(263)+(268)-(277)+(280)-(281)+(283)
77002 13 2

18

XHE CALIFOBNIA-WASHINGTON ABC OF PRIMARY TRIANGULATION.

ACCURACY AS INDICATED BY CORRECTIONS TO OBSERVED DIRECTIONS.

The corrections to observed directions resulting from the figure adjustments indicated by
the preceding observation equations are as follows:

Table of corrections to observed directions.

Number of

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

19

Table of corrections to observed directions Continued.

Number of
f*

20

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANOULATION.

Table oftnan^a.

station

THE CALirOBNlA-WASHINGTON ABC OP PBIMABY TBIANGULATION.

ai

TcMe of triangles Continued.

^

station

22

THE CALIFORNIA-WASHINGTON ABC OF PRIMABV TBIANOULATION.

Table of triangles Continued.

station

THE CALirORNIA-WASHINGTON AEC OF PRIMARY TRIANGULATIOH".

23

Table of triangles^-Gontiaxx&A.

station

24

THE CALIFORNIA-WASHINGTON ABC OF PRIMARY TRIANGULATION.

Table of triangles Continued.

Sutkm

THE CALIFOBNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

25

Table of triangles Continued.

station

26

THE CALLFOBNIA-WASHINGTON ABC OF PRIMARY TBIANGULATION.

Table of triangles Continued.

Station

THE CALIFORNIA-WASHINGTON AKC OF PEIMARY TBIANGULATION.

27

Table of triangles Continued.

station

28

THE CAUFOBNIA-WASHINGTON ABO OF PRIMABY TBIANGUUATION.

Table of triangles Continued.

station

THE CALIFORNIA-WASHINGTON ARC OF PKIMABY TBIANGULATION.

29

Table of triangles Continued.

^

station

30

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY THIANGULATION.

Ill solving the normal equations in each section of the figure adjustment the length equation

was, as usual, assigned to the last place, so that after all the conditions relating to triangle clo-

sures and ratios of length had been satisfied the discrepancy in length became known. In the

following table the discrepancies developed between bases are given in terms of the seventh place

A of logarithms and are also expressed as ratios.

plus sign before the discrepancy expressed in

terms of logarithms means that the first base mentioned is longer as measured than as computed

through the mtervening triangulation from the second base mentioned.

Bases

THE CALIFORNIA-WASHIKGXON ARC OF PRIMARY TBIANGULATION.

* 31

an observed direction and the number of conditions and directions.' The amount actually developed was 10".l. In the California arc, of which the California-Washington arc is a continuation, the error in azimuth expected at its extremity, near San Diego, was 2".9, even though.the azimuth was carried through 1,250 miles (2,000 kilometers) in the transcontinental triangulation and 500 miles (800 kilometers) through the California arc. The actual accumulated error in azimuth found at San Diego was 8". 8. At San Diego the correction to reduce to liaplace or true azimuth was minus, whereas at Tacoma the required correction was plus.
Confronted with these values for twist, the writer suggests that they may be caused by the
unequal heating of the theodolite by the sun, even though the theodolite is protected from the
direct rays. On triangulation extending in a north and south direction, as this arc does, where the observations were mainly made in the late afternoon, the west side of the instrument is
undoubtedly warmer than the east side and the resulting angles opening to the west and to the east should be subject to systematic errors of opposite signs, and therefore twist would develop. If this theory is correct, an east and west arc should develop only a small amount of twist, well within the limits for the expected error. Arcs on which the observing was done at night should develop no twist exceeding that allowed by the probable error, for the temperatm-e of the east and west sides of the instrument would be equal. It is expected that this theory will be tested in the near future on all of the arcs of primary triangulation now existing in the United States.

EXPLANATION OF POSITIONS, LENGTHS. AND AZIMUTHS, AND OF THE UNITED STATES STANDARD DATUM.

The lengths, as already fully explained in connection with the adjustments, all depend upon the Yolo, Willamette, and Tacoma bases. The lengths as given are all reduced to sea level.

If the actual length of a line simply reduced to the horizontal is desired, it may be obtained with all the accuracy ordinarily needed by adding to the sea-level length as given a correction =

,

, ,.

. . Tmean elevation of the two ends of the line in meters"! ^m

Oength of line as given)

6S70000

'

maxi-

mum value of this correction does not exceed ^Ao for the length of any portion of the
triangulation here published. The maximum error made in the use of the above approximate
formula for the correction does not exceed o o^o o o ^Q^ the length of any portion of this triangulation. The positions that is, the latitudes, longitudes, and azimuths need special explanation. All of the positions and azimuths have been computed upon the Clarke spheroid of 1866,
as expressed in meters, which has been in use in the United States Coast and Geodetic Survey

for many years.
After a spheroid has been adopted and all the angles and lengths in a triangulation have

been fully fixed, it is still necessary, before the computation of latitudes, longitudes, and azimuths can be made, to adopt a standard latitude and longitude for a specified station and a

standard azimuth of a line from that station. For convenience, the adopted standard position

(latitude and longitude) of a given station, together with the adopted standard azimuth of a

line from that station, is called the geodetic datum. The primary triangulation in the United States was commenced at various points and
existed at first as a number of detached portions, in each of which the geodetic datum was neces-

sarily dependent only upon the astronomic stations connected with that particular portion.
As examples of such detached portions of triangulation there may be mentioned the early triangulation in New England and along the Atlantic coast, a detached portion of the transcon-
tinental triangulation centering on St. Louis and another portion of the same triangulation in the Rocky Mountain region, and three separate portions of triangulation in California in the latitude of San Francisco, in the vicinity of Santa Barbara Channel, and in the vicinity of San
Diego. With the lapse of time these separate pieces have expanded until they have touched

or overlapped.

See Figure ol the Earth and Isostasy from Measurements iu the United States, p. 120.

88

THE CALIFOBNIA-WASHINGTON ABC OF PRIMARY TRIANGULATION.

The transcontinental triangulation, of which the office computation was completed in 1899, joins all of the detached portions mentioned and makes them one continuous triangulation. As soon as this took place the logical necessity existed of discarding the old geodetic data used in these various pieces and substituting one for the whole country, or at least for as much of the country as is covered by continuous triangulation. To do this is a very heavy piece of work
and involved much preliminary study to determine the best datum to be adopted. On March 13, 1901, the superintendent adopted what is now known as the United States Standard Datum,
and it was decided to reduce the positions to that datum as rapidly as possible. The datum
adopted was that formerly in use in New England, and therefore its adoption did not affect the positions which had been used for geographic purposes in New England and along the Atlantic coast to North Carolina, nor those in the States of New York, Pennsylvania, New Jersey, and
Delaware. The adopted datum does not agree, however, with that used in The Transcontinental Triangulation and in The Eastern Oblique Arc of the United States, publications which
deal primarily with the purely scientific problem of the determination of the figure of the earth
and which were prepared for publication before the adoption of the new datum. As the adoption of such a standard datum is a matter of considerable importance, it is in
order here to explain the desirability of this step more fully. The main objects to be attained by the geodetic operations of the United States Coast and
Geodetic Siirvey are, first, the control of the charts published by the Survey; second, the furnishing of geographic positions (latitudes and longitudes), of accurately determined elevations, and of distances and azimuths, to officers connected with the United States Coast and Geodetic
Survey and to other organizations; third, the determination of the figure of the earth. For the first and second objects it is not necessary that the reference spheroid should be accurately that which most closely fits the geoid within the area covered, nor that the adopted geodetic datum should be absolutely the best that can be derived from the astronomic observations at hand. It is simply desirable that the reference spheroid and the geodetic datum adopted shall
be, if possible, such a close approximation to the truth that any correction which may hereafter be derived from the observations which are now or may become avaUable shall not greatly exceed
the probable errors of such corrections. It is, however, very desirable that one spheroid and one geodetic datum be used for the whole countrj'. In fact, this is absolutely necessary if a
geodetic siu"vey is to perform fully the function of accurately coordinating all stirveys within
the area which it covers. This is the most important function of a geodetic survey. To perform this function it is also highly desirable that when a certain spheroid and geodetic datum
have been adopted for a country they be rigidly adhered to, without change, for all time, unless
shown to be largely in error.
In striving to attain the third object, the determination of the figure of the earth, the con-
ditions are decidedly different. This problem concerns itself primarily with astronomic observations of latitude, longitude, and azimuth, and with the geodetic positions of the points at which the astronomic observations were made, but is not concerned with the geodetic positions of
other points fLxed by the triangulations. The geodetic positions (latitudes and longitudes) of comparatively few points are therefore concerned in this problem. However, in marked contrast to the statements made in preceding paragraphs, it is desirable in dealing with this problem that, with each new important accession of data, a new spheroid fitting the geoid with the greatest possible accuracy, and new values of the geodetic latitudes, longitudes, and azimuths of the
highest degree of accuracy, should be derived.
The United States Standard Datum was adopted with reference to positions furnished for
geographic purposes, but has no reference to the problem of the determination of the figure of the earth. It is adopted with reference to the engineer's problem of furnishing standard positions and does not affect the scientist's problem of the determination of the figure of the earth.
The principles which guided in the selection of the datum to be adopted were: First, that the adopted datum should not differ widely from the ideal datum for which the sum of the station errors in latitude, longitude, and azimuth should each be zero; second, it was desirable that the adopted datum should produce minimum changes in the publications of the Survey,

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TBIANGULATION.

33

including its charts; and, third, it was desirable, other things being equal, to adopt that datum
which allowed the maximum number of positions already in the office registers to remain unchanged, and therefore necessitated a minimum amount of new computation. These consid-
erations, led to the adoption as the United States standard of the datum which had been in use
for many years in the northeastern group of States and along the Atlantic coast as far as North
CaroUna.
An examination of the station errors available in 1903, on the United States Standard
Datum, at 246 latitude stations, 76 longitude stations, and 152 azimuth stations, scattered widely over the United States from Maine to Louisiana and to California, indicated that this datum approaches closely the ideal with which the algebraic sum of the station errors of each class would be zero.'
The adopted United States Standard Datum, upon which the positions and azimuths
given in this publication depend, may be defined in terms of the jjosition of the station Meades
Ranch as follows:

^ = 39 13 26.686 = >i 98 32 30.506 a to Waldo =75 28 14.52

Points are then said to be upon the United States Standard Datum when they are connected with the station Meades Ranch by a continuous triangulation, through which the cor-
responding latitudes, longitudes, and azimuths have been computed on the Clarke spheroid of 1866, as expressed in meters, starting from the above data.
The principal hsts of geographic positions heretofore pubhshed on the United States Standard Datum throughout the whole United States are contained in the following publications of the United States Coast and Geodetic Survey and of other organizations:
Appendix 8 of the Report for 1885, positions in Massachusetts and Rhode Island; Appendix 8 of the Report for 1888, positions in Connecticut; Appendix 8 of the Report for 1893, positions in Pennsylvania, Delaware, and Maryland; Appendix 10 of the Report for 1894, positions in Massachusetts; Appendix 6 of the Report for 1901, positions in Kansas and Nebraska;
Appendix 3 of the Report for 1902, positions in Kansas, Missouri, Nebraska, and Colorado; Appendix 4 of the Report for 1903, positions in Kansas, Oklahoma, and Texas; Appendix 9 of
m the Report for 1904, positions in California; Appendix 5 of the Report for 1905, positions
Texas; Appendix 3 of the Report for 1907, positions in California; Appendix 5 of the Report
for 1910, positions in California; Appendix 4 of the Report for 1911, positions in Nebraska, Minnesota, North Dakota, and South Dakota; Appendix 5 of the Report for 1911, positions in
Texas; Appendix 6 of the Report for 1911, positions in Florida; Special Publication No. 11,
positions in Texas, New Mexico, Arizona, and California; in Appendix EEE, pages 2905-3031,
Annual Report of the Chief of Engineers, 1902, positions of points on or near the Great Lakes; in the publications of the Massachusetts Harbor and Land Commission; and in various bulletins
of the United States Geological Survey.

TABLE OF POSITIONS.

In the tables of positions the latitude and longitude of each point are given on the United
States Standard Datum (see p. 31), also the length and azimuth of each line observed over,
whether in one or both ways. Along with the latitude and longitude of each point the lengths
and azimuths are given of lines from that point to other points of the triangulation. No lengths
or azimuths are repeated, and for a given line the length and azimuth will generally be found opposite the position of the last mentioned of the two stations involved.
For the convenience of the draftsman a column of "seconds in meters" is given, in which is placed the length (in meters) of each small arc of a meridian or parallel corresponding to the
' Thb Is further borne out in the reduction of 765 astronomic stations in connection with the "Supplementary investigation inl909oftlie figure of the earth and isostasj," bj- J. F. Hayford, published by the U. S. Coast and Geodetic Survey.
77002 13 3

84

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANOULATION.

seconds of the given latitude or longitude. To facilitate further the use of the tables, a column is given of the logarithms of the lengths. It must be remembered that it is the logarithm
which is derived first from the computation, the lengths given in this table being then derived
from the corresponding logarithms. The rule followed in recent publications of this Office has been to give latitudes and longi-
tudes to thousandths of seconds for all points the positions of which are fixed by fully adjusted triangulation. Points, the positions of which are given to hundredths of seconds only, are marked by footnotes as being without check (observed from only two stations) or checked by
verticals only.
In the columns giving azimuths, distances, and logarithms of distances, the accuracy is indicated to a certain extent by the number of decimal places given, it being understood that in each case two doubtful figures are given. In some cases there is verj' little doubt of the cor-
rectness of the second figure from the right, while in a few cases some doubt may be cast on the
third figure from the right.
These tables may be conveniently consulted by using as finders the seven sketches at the
end of this appendix, and the index on pages 75 to 78. In the third column of the index will be found for each point a reference to the page on which its description is given, in the fourth column the number of the sketch on which it appears, and in the fifth column the page on which
its elevation above sea level will be found.
For the convenience of those who wish to convert the distances given in this table or the
elevations given later on from meters into feet the following conversion table is here inserted:

Meters

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

35

station

se

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

Station

THE CALIFOBNIA-WASHINGTON AHC OP PRIMAEY TRIANGULATION.

37

station

88

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

Statioa

THE CALIFORNIA-WASHINGTON AKC OF PRIMARY TRIANGULATION.

39

Station

40

THE CAUFOBNIA-WASHINGTON ABC OF PKIMABY TBIAUGULATION.

Station

THE CALIFOKNIA-WASHINGTON ABC OF PRIMARY TRIANGULATION.

41

station

42

THE CALIFORNU-WASHINGTON ABC OF PRIMABY TBIANGULATION.

Station

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

43

& and has a polished center surrounded by the raised letters "U. S. C. G.S." and a raised flange
around the edge. The shank is 25 mm. in diameter and 75 mm. long, with a slit at the lower
end into which a wedge is inserted so that when it is driven into a drill hole in the rock, it will bulg^ at the bottom and so hold the mark securely in place.

GENERAL NOTES IN REGARD TO STATION MARKS.

A Note 1.

three-eighths-inch copper bolt 3 inches long is cemented into a drill hole in

the rock, and directly above the bolt in the same drill hole is cemented an old-type station mark,

A described in the preceding paragraph.

cross in the top of the copper bolt and another in the

polished center of the disk mark the station.

Note 2. This markmg is similar to that described in note 1, except that the copper bolt

and the disk are in separate bowlders and the bowlder containing the bolt is at some distance

beneath the surface. The cross on the disk is directly above the one on the bolt. The dimen-

sions of the bowlders are given in the description of the station.

Note 3. The station is marked by an old-type station mark, described above, cemented

into a drill hole in the rock. No underground mark was used.

REFERENCE MARK.

Note 4. This mark is a drill or punch hole in the top of a three-eighths-inch copper bolt 3
inches long, which is leaded or cemented into a drill hole in a rock with the top of the bolt flush with the surface.
PRINCIPAL POINTS.

Mount HelerM (Napa County, Cal., W. E., 1876; 1908). On the summit of Mount Helena,

about 12 miles to the northward of Calistoga. The station was originally marked by a fine

drill hole and cross in the top of a one-half-inch copper bolt 5 inches long, which was cemented

in a drill hole in bedrock, and by a brick pier 3 bricks square and 43 inches high, built over the
bolt. When visited in 1908 it was found that the pier had been dynamited. Other instrument

piers are at the following distances and directions from the station: Collimator pier, 2 bricks

square and 61 inches high, 2.27 meters northwest; transit pier, 2 by 3 bricks and 39 inches

high, 17.04 meters southwest; latitude pier, 2 by 2^ bricks and 36 inches high, 17.74 meters

southwest of the station and 1.68 meters east of the transit pier; vertical angle pier, 2 bricks

square and 44 inches high, 33.31 meters southwest of the station and 16.92 meters a little south

A of east of the latitude pier.

boundary mark between Lake and Napa Counties, a large

drill hole in a basaltic rock, is 2.18 meters northwest of the station.

Marysville Butte (Sutter County, Cal., W. E., 1876; 1904). About 15 miles west of Marys-

ville on the southeastern summit of the south butte of the Marysville Buttes, about 6 meters

northeast of the highest part of the summit, and near the steep on clifi^ the north side. The

station is marked by an old-type station mark, described on page 42, set in a drill hole in a small

rock embedded in the concrete that fills a depression in the solid rock. Below the concrete and

directly under the station mark is a three-eighths-inch copper bolt 3 inches long set in a drill

hole in the solid rock. Three reference nxarks, each of which is a tlu-ee-eighths-inch copper bolt

3 inches long set in a drill hole in the rock, are at the following distances and azimuths from the

station: 2.470 meters, 246 48'; 2.635 meters, 5 06'; and 2.915 meters, 103 07'.

Snmo Mountain west (Glenn and Lake Counties, Cal., E. F. D., 1892; 1904). On the

highest point of the southwest summit of Snow Mountain. The summit is about 300 meters

long in a northwest and southeast direction and about 50 meters wide at the station and is

covered with small broken stones. There are a few scrub pines just below the pitch of the ridge

about 100 meters southeast of the station. The station is marked by a one-half-inch brass bolt

3 inches long in a drill hole in the solid outcropping rock, and by a concrete pier 12 inches square

and 44 inches high having embedded in its top a brass bolt directly above the one in the solid

rock.

44

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRUNGULATION.

Snow Mmintain east (Glenn County, Cal., W. E., 1876; 1904). On the northernmost rock-croppings at the edge of the summit of the eastern peak of Snow Mountain, about 5 miles
south of Mount St. John and near the corner of Lake, Colusa, and Glenn Counties. The sta-
tion is marked by a half-inch copper bolt cemented in a drill hole in a hollow at about the middle of the highest point of rocks, with the top of the bolt about a half inch above the surface and marked by a cross. The reference marks are all drill holes in rocks, the first being distant 5.16 meters in azimuth 59 57', the second 3.33 meters in azimuth 165 39', and the
third 6.89 meters in azimuth 248 38'.
Kent (Tehama County, Cal., O. B. F., 1904). On a high ridge about 8 or 10 miles east by south from Mount Linn and about 18 miles by road in a northwesterly direction from Paskenta, on a peak locally known as Bald Rock, on a ledge on the east side of the summit and
about 8 or 9 feet lower than its highest part. Four or five hundred feet to the westward of the station and about 50 or 60 feet lower is a large, prominent, rocky knob. The station is marked according to note 1.' The reference marks are described in note 4.' The first one is in a large rock distant 5.01 meters in azimuth 212 40', the second in a flat ledge distant 70.19 meters in azimuth 285 50', and the third on the largest part of the ledge distant 47.72 meters
in azimuth 5 17'.
Lyons (Tehama County, Cal., O. B. F., 1904). About 5 miles east of Lyonsville post ofiice on a ridge known locally as Bald Hill, about 300 yards from the summit of the ridge on the shoulder extending toward Lyonsville and in the middle of a large group of bowlders.
A lone fir tree stands about 50 meters south by east from the station. The station is marked
according to note 1.' Two reference marks described in note 4,' are in large rocks and at the
following distances and azimuths from the station: 29.69 meters, 126 59'; and 20.22 meters,
332 22'.
BaUy (Shasta County, Cal., O. B. F., 1904). On the northernmost of the two main peaks
on the summit of Bally Mountain, a prominent and well-known mountain about 15 miles by road west of Redding. The station mark, described in note 1,' is in the top of a rock on the north side of the most prominent group of rocks on the peak and 5 or 6 feet below the top of
the group. Two reference marks, described in note 4,' are at the following distances and
azimuths from the station: 4.29 meters, 247 07'; and 10.62 meters, 154 49'.
Round (Shasta County, Cal., O. B. F., 1904). On the highest part of what is known as Round Mountain just north of the post office of the same name. The station mark, described in note 1,' is in a large bowlder which projects about 6 inches out of the ground. Two refer-
ence marks, described in note 4,' are at the following distances and azimuths from the station: 28.72 meters, 345 30'; and 6.43 meters, 57 13'. The south reference mark is in the most eastern rock of a prominent group of rocks near the south end of the summit.
Sjmr (Siskiyou County, Cal., O. B. F., 1904). On the west slope of Mount Shasta at an
elevation of about 9,100 feet, in a position best identified by approaching the summit from Igema, by the road leading through Kite Canyon. In ascending this route several prominent peaks are discerned ahead and from the right-hand one a narrow shoulder extends in a westerly direction, or toward Black Butte. The station is about 50 meters below an abrupt change of slope of the ridge of this shoulder, and about 1 mile from the jieak mentioned above.
The station mark, described in note 1,' is in the top of a large rock flush with the ground. Two
reference marks described in note 4,' are at the following distances and azimuths from the
station: 13.77 meters, 165 53'; and 8.10 meters, 228 47'. Mears (Shasta County, Cal., O. B. F., 1904). About 4 or 5 miles west by south from
Castella and about southwest from Castle Crags, on the southern summit of the highest rocky peaks in the region known locally as Gray Rocks. The station is about 20 feet below the highest part of the peak and near the bluff on the south and east sides, with a ledge 3 or 4 feet higher about 10 feet distant toward the southeast. The peak was approached from the south and the 30-foot bluff near the station surmounted by means of ladders. The station
1 See p. 43.

THE CALIFOKNIA-WASHINGTOlf ARC OF PRIMARY TRIAKGULATION.

45

is marked according to note 1.' Two reference marks, described in note 4,' are located as
follows: The first in a bowlder near the trail to the station, and distant 7.92 meters in azimuth 70 50'; and the second, on a low bowlder east of a high pointed rock, and distant 17.77 metfys in azimuth 143 0.3'.
Boliver (Siskiyou County, Cal., O. B. F., 1904). On the north side of a large group of bowlders about 60 yards northeast of the highest part of the summit of Mount Scott, known
locally as Old Craggj- or Boliver, which is the high peak about 5 miles in a southerly direction
from Callahan. The station is marked according to note 1.* Two reference jnarks, described
in note 4,' are at the following distances and azimuths from the station: 6.57 meters, 272 41'; and 9.88 meters, 107, 47'.
Soda (Jackson County, Oreg., O. B. F., 1904). On a peak known locally as Old Baldy,
in the Siskiyou range of mountains, about 20 miles by road and trail southeast of Ashland and 5 miles east by north from Pilot Rock, a prominent peak in the same range. The best approach is from Ashland via Soda Springs and Davis' ranch. The station mark, described
in note 1,' is in a large rock whose upper surface is flush with the ground. Two reference
marks, described ui note 4,' are in bowlders whose tops are but slightly above ground and at the following distances and azimuths from the station: 12.91 meters, 299 53'; and 23.95
meters, 35 36'.
Gazelle astronomic station (Siskiyou County, Cal., O. B. F., 1904; 1908). About 250 yards north by east from the Gazelle railroad station near the center of the top of a very prom'ment knoll and about 40 feet northeast of the largest bowlder on the knoll. The station mark, described in note 1 } is in a rock below the surface of the ground. Three reference marks, described in note 4,' are at the following distances and azimuths from the station: 19.20 meters, 290 12'; and 6.40 meters, 137 39'.
Sterling (Jackson County, Oreg., O. B. F., 1904). In the Siskiyou range of mountains, about
25 miles southwest of Ashland and 2 miles west of Mount Sterling, on the northernmost summit
of a ridge just south of tiie Silver I^'ork basin and at the western end of the long east-and-west valley which is just north of Mount Sterling. The station is about 80 or 90 meters southeast of the highest point of the summit in the center of a group of small bowlders. The station
mark, described in note 1,' is in the top of a large rock. Two reference marks, described in
note 4,' are at the following distances and azimuths from the station: 34.85 meters, 18 13';
and 20.44 meters, 136 03'.
Riist (Jackson Count}-, Oreg., O. B. F., 1904). On the highest summit of the peaks known
locally as the Black Buttes (Rustler on U. S. Geological Survey maps), about 20 miles north of Mount Pitt and 26 miles by road and trail from Big Butte post office via Parker's ranch. The
station is marked according to note 1.' Two reference marks, described in note 4,' are at the
following distances and azimuths from the station: 11.995 meters, 264 33'; and 10.12 meters,
337 53'.
Onion (Douglas County, Oreg., O. B. F., 1904). On the highest part of the bare summit
of Onion Springs Mountain, about 1 mile south of the Onion Sj^rings, and best reached from Glendale via Galesville and Gilpatrick's ranch. The station mark, described in note 1,^ is in a
rocky ledge. Two reference marks, described in note 4,' are located as follows: One in a
prominent ledge and 24.62 meters from the station in azimuth 91 50', and the other in an inconspicuous, low bowlder at the western edge of the summit and distant 47.22 meters in azimuth 182 47'.
Blacic (Douglas County, Oreg., O. B. F., 1904). Near the northeast comer of the highest part of the summit of Black Rock, a high, prominent, rocky peak about 40 miles in a direct line east of Roseburg and north and northwest of some near-by higher wooded peaks. The
station mark, described in note 1,' is in the solid rock of the summit. Two reference marks,
described in note 4,' are also in solid rock and at the following distances and azimuths from
the station: 13.78 meters, 4 55'; and 6.47 meters, 297 45'.
' See p. 43.

46

THE CALIFOBNU-WASHINGTON ABC OF PBIMABY TBIANGULATION.

While (Douglas County, Oreg., O. B. F., 1904). On the highest part of the summit of

White Rock, a prominent peak about 15 miles east of Rosebui^. The station mark, described

A in note 1,' is in a large bowlder.

reference mark, described in note 4,' is in a large bowlder

just east of a prominent ledge and is 34.44 meters from the station, in azimuth 353 11'.

Scott (Douglas County, Oreg., O. B. F., 1904). On the highest part of the summit of Mount

Scott, about 20 miles northeast of Roseburg. The station mark, described in note 1,' is in a

large bowlder. Two reference marks, described in note 4,' are located as follows: One in a

white rock at about the middle of a prominent ledge and 32.71 meters from the station in

azimuth 195 02'; and the other in a rocky ledge near the edge of the brush and 18.17 meters
m distant azimuth 305 42'.

Fairview (Lane County, Oreg., O. B. F., 1904). On the west side of the summit of Fair-
view Peak in the Bohemia Mountains, about 25 miles southeast of Cottagegrove and 6 nules by road from Mineral post office. The station mark, described in note 1,' is in a bowlder. Three reference marks described in note 4,' are in rock ledges and at the following distances and azimuths from the station: 6.69 meters, 74 29'; 2.92 meters, 181 39'; and about 175 feet,

266 09'.

Yellow (Douglas County, Oreg., O. B. F., 1904). On the highest summit of the timbered
ridge about 10 miles west of Yoncalla. The station is marked according to note 2,' the subsurface mark in a bowlder 8 by 12 by 16 inches placed 18 inches beneath the surface, and the surface
mark in a bowlder 10 by 20 by 30 inches, the top of which is flush with the surface of the ground.
A reference mark, described in note 4,' is in a rock ledge and 22.62 meters from the station in
azimuth 334 37'. Two other reference marks, consisting of three-sixteenths inch copper wires
3 inches long set in bowlders, are at the following distances and azimuths from the station :

21.04 meters, 197 31'; and 20.70 meters, 107 02'.

Spencer (Lane County, Oreg., O. B. F., 1903). This station is near a United States Geological Survey station. It is on the south end and highest point of the summit of Spencer Butte,
about 4 miles south of Eugene. Two trees used by the Geological Survey are at the north end

of the summit, which is in the form of a ridge. The station is marked according to note 1 .'
Two reference marks, described in note 4,' are in rocks near the station, one distant 5.338

meters in azimuth 175 02', and the other 4.570 meters in azimuth 328 51'. The Geological Survey station is 7.970 meters from the station in azimuth 176 12'.
Roman (Douglas County, Oreg., O. B. F., 1903; 1908). On the most westerly of the two summits of the highest peak of the Coast Range, known as Roman Nose or Saddle Mountain,

situated near the north line of Douglas County about 5 miles southwest of the junction of Wild Cat Creek with the Siuslaw River. It is on the highest point of the summit, about 6 feet from the southern edge of the bluff and 20 feet from the steep part of the slope east of the station. The peak is bare except for a few low shrubs, and has a steep bluff on the south side and a gentle grassy slope on the north side. The station is marked according to note 2,' the subsurface mark

in a bowlder 12 by 12 by 24 inches, 18 inches below the surface, set with the axis east and
west, and the surface mark in a bowlder measuring about a foot on each side. Two reference marks, described in note 4,' are located as follows: One in the nearest outcropping of the solid
rock 14.760 meters from the station in azimuth 148 06', and the other in a projecting bowlder 6.775 meters from the station in azimuth 205 33'. Arrows pointing to the reference marks
are cut in the rock near each mark. An old burned stump is about 5 feet from the station in
azimuth 232.

Mary (Benton County, Oreg., O. B. F., 1903; 1908). On the highest point of the grassy summit of Mary Peak, about south-southwest from CorvaUis. The station is marked according
to note 2,' the subsurface mark in a flat stone 4 inches thick and 19 inches in diameter 22 mches
below the surface, and the surface mark in a bowlder 16 by 18 by 30 inches, the top of which is flush with the surface of the ground. Two reference marks, described in note 4,' are in bowlders, and at the following distances and azimuths from the station: 13.77 meters, 326 22'; and

29.36 meters, 58 11'.

I See p. 43.

THE CALIFOENIA-WASHINGTON ABC OF PRIMARY TRIANGULATION.

47

Peterson (Linn County, Oreg., O. B. F., 1903). About 4 miles southwest of Lebanon on

the highest part of the most westerly of the two summits known as Peterson Butte. The station is marked according to note 1 .* Two reference marks, described in note 4,' are located

us follows: One in the lower part of the northerly sloping face of the largest rock on the south

side of the summit, and 4.645 meters from the station in azimuth 7 30'; and the other in the

ledge just east of the largest rock on the north side of the summit, and 3.270 meters distant in

azimuth 185 00'.

Twin (Linn County, Oreg., O. B. F., 1905). On the farm of Mr. Gentry near the southwest

comer of sec. 24, T. 14, R. 3 W., about 6 or 7 miles from Rowland. It is on the highest summit

of a partly wooded ridge, the south slope being bare and the north slope wooded, and about

8 or 10 meters southeast of the highest point of the summit. The station is marked according to note 2,' the underground mark in a stone about 2 feet below the surface and the surface mark

in a large stone about 6 inches below the surface. Three reference marks, described in note 4,'

are at the following distances and azimuths from the station: 6.66 meters, 314 42'; 6.39 meters, 53 57'; and 6.87 meters, 155 44'. The last^mentioned reference mark is near the highest

point of the summit.
Ridge (Lane County, Oreg., O. B. F., 1905). On the highest part of a ridge on land owned

by Mr. J. J. Winn, about 1^ miles north of his residence, and about 10 miles by road in a north-

westerly direction from Junction City. The station is marked accordmg to note 2,' with the

subsurface mark 1.5 feet below the surface. Three reference marks, described in note 4,' are

in inconspicuous bowlders flush with the surface of the ground, and at the following distances

and azimuths from the station: 4.86 meters, 164 32'; 30.69 meters, 278 43'; and 9.73 meters,

A 356 15'.

triangular blaze in a large maple tree is 11.63 meters from the station in azimuth

92 16', and a similar blaze in a large fir tree is 8.45 meters distant in azimuth 213 33'.

Ranch (Lane County, Oreg., O. B. F., 1903). About 12 miles west by south from Eugene,

2^ mUes southwest of Llewellyn post office and about one-haK mile west of the road leading from Llewellyn to Crow post office, on land belonging to Mrs. Frances Ranch. It is about 150

meters east of the summit on the north side of a sloping ridge about 300 feet higher than the

valley through which the road runs, the first prominent ridge encountered in going from Llewel-

lyn to CYow and the only ridge in the vicinity from which Willamette south base can be seen.

The station is about 200 feet west of a point where the ridge becomes steeper. The station was marked according to note 2,' the undei^ound mark in a small flat stone 2 feet below the surface
and the surface mark in a rock about 12 by 12 by 18 inches flush with the surface. Two refer-

ence marks, described in note 4,' are located as follows: One in a rock 10 by 10 by 18 inches on

the highest part of the ridge and 11.96 meters from the station in azimuth 286 02', and the

other in a rock 6 by 8 by 14 inches distant 12.22 meters in azimuth 51 46'.

Willamette south base (Lane County, Oreg., O. B. F., 1903; 1908). About 5 mQes from

Eugene and 220 meters south of the Eugene-Elmira road on land belonging to William Nelson..

It is about 100 meters north of a large gravel pit, 78 meters from the line fence between William
Nelson and M. Nelson, and about in line with the west face of the bam belonging to WiUiam

Nelson which is 86.79 meters north of the station. The station is marked with old-type station

mark described on page 42, placed in the center of a 6-inch drain tile and both embedded in a

piUar of concrete 2 feet long, 36 inches in tliameter at the base, 18 inches in diameter at the top,
and set in the ground so that the tops of the pillar and tile and station mark are all flush with

the surface of the ground. Six inches below the foot of this pillar a cross in the top of a

i-inch copper bolt, embedded in a block of concrete 10 by 24 by 24 inches, forms the subsur-

face mark. In 1906 a concrete pillar 2^ feet high, 18 inches square at the base and 12 inches

square at the top, with the letters ' ' U. S. C. S." on the south side, was set over the surface mark. The first reference mark is a ^-inch copper bolt in a concrete block 12 by 12 by 18 inches,

the top of which is flush with the ground with a similar block and bolt directly beneath it as

subsurface mark, distant 212.29 meters from the station in azimuth 177 32' 02". The second

mark, similar to the first, is at the junction of the road fence and that dividing the farms of

' See p. 43.

48

THE CALIFORNIA-WASHINGTON ABC OF PRIMARY TRIANGULATION.

William Nelson and M. Nelson, and 225.16 meters from the station ui azimuth 200 19' 30".

The third reference mark, similar to the preceding two but with no subsurface mark, is in the line of the boundary fence 78.38 meters from the station in azimuth 265 16' 42". The fourth mark is a i-inch copper bolt leaded into a drill hole in a large stone in the southwest comer of the foundation of the main part of William Nelson's barn, and is 86.79 meters from the station in

azimuth 181 30' 16".

Willamette north hose (Lane County, Oreg., O. B. F., 1905; 1908). One and one-,half miles south and one-half mile west of Junction City in the east center of sec. 7, T. 16, R. 4 W., on land owned by Mr. William M. Pittney of Junction City. It is in the northeast comer of a field on the south side of the main east-and-west road, about 71 yards from the north-and-

south fence to the east and 4 or 5 j-ards from the fence on the south side of the road, and almost opposite the main gate wliich leads into the barnyard corral of the farm across the road. The subsurface station mark is a three-eighths inch copper bolt 6 inches long, set in a block of concrete 3^ by 4 feet and 10 iaches deep, placed 3 feet below the surface. The surface mark is an old-type station mark described on page 42, set in the top of a concrete pier 3^ feet square at the base, 1^ feet square at the top, and 2 feet 5 inches deep, the top of which is flush with the surface of the ground. Surrounding the station mark and embedded in the concrete is an 8-inch drain tile 1 foot long with its rim about flush \ni\\ the top of the pier. Each of the three reference marks consists of two three-eighths inch copper bolts, 3 inches long, each set in the top of a concrete post 1 foot square, the subsurface post being 9 inches long and 2^ to 3 feet below the surface, and the surface mark about 2 feet long, with its top 4 inches below the surface, The first reference mark is 6 inches south of the fence on the south side of the road and about in

the prolongation of the fence line on the west side of the corral mentioned above, and is 32.058

meters from the station in azimuth 97 10'. The second mark is in the corral across the road,

mam about 10 inches from the road fence and 6 or 8 feet east of the east end of the

road gate,

and is 19.876 meters from the station in azimuth 186 24'. The third mark is on the south side

of the main road, 12 or 15 feet from the road fence, and 6 inches west of the north-and-south

fence, at a distance from the station of 65.076 meters in azimuth 271 26'.

Seavies 2 (Lane County, Oreg., W.H. B., 1908). In the same locality as Seavies (U. S. 6. S.).

(See p. 56.) It is on the south slope of the peak near the lower edge of the first timber from the

top and almost in luxe witli Spencer (see p. 46) and the tangent line to the west bank of the

McKensie River at the big curve in the flat below the station. The station is marked by a drill

hole in the rock and by piles of rock around the tripod erected at the station.
Pisgah (Lane County, Oreg., W. H. B., 1908). Located north and east from Goshen on a

hill known as Mount Pisgah, about 200 feet southwest, or toward Spencer Butte, from the

highest point of the liiU. The station is on top of a rock about 4 by 6 feet in area, projecting

16 inches above the ground, the largest one of a cluster of rocks and, with the exception of a

large rock on the west slope about 175 feet to the north, the lai^est rock in the vicinity. Sta-

tion is marked by a one-half inch drill hole 1 \ inches deep, 6 inches from the west edge of the

rock and 23 inches from its south point.

Eugene astronomic station (Lane County, Oreg., O. B. F., 1904; 1908). This station is

identical with the United States Geological Survey station. It is on the east end of Skinners

Butte, near Eugene, Oreg., just above the reservoir and north of the railroad station, on the

site of the old observatory of Oregon State University. It was learned in 1908 that the land

was to be converted into a park and that the station would be demolished, so two marble refer-

ence stones, ])rojectlng 2 inches above the surface and bearing on the top the letters "U. S."

with a cross between, were set to preserve the station. The first 5 by 5 by 18 inches is 18.294

m meters from the station in azimuth 119 59', and the second, 4 by 7 by 14 inches size is on

A the south brow of the hill 12.211 meters from the station in azimuth 52 47'.

large con-

crete "O" on the brow of the hill overlooking the railroad station is in azimuth 2 from the

station. The distance between the two reference marks is 17.625 meters, and from the first

reference mark the Patterson School spire is in azimuth 315 28', and the spire of the Humphrey

Memorial Methodist Cliurch is in azimuth 353 53'.

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATXON.

49

Yam (Polk County, Oreg., O. B. F., 1903; 1908). On the highest point of the highest of

a group of hills about 12 miles northwest of Salem, and about 10 meters south of a wire fence

A which passes over the summit.

shghtly lower wooded hill is about a haK mile northwest of

the staMon and a group of hiUs is about halfway between the station and Salem. The station

is marked according to note 2,' the surface mark in a bowlder 15 by 18 by 18 inches with its

top flush with the surface of the ground, and the subsurface mark in a bowlder 8 by 16 by 16

inches and 23 inches below the surface mark. Two reference marks, described in note 4,' are

in bowlders about 14 by 18 by 18 inches with their tops flush with the surface of the ground,

and with a few loose stones pded about them for identification. One is in the Une of the wire

fence, 11.06 meters from the station in azimuth 197 10', and the other 8.59 meters from the

station in azimuth 329 07'.

Hult (Marion County, Oreg., O. B. F., 1903). On a prominent bare liill about 6 miles
by road and 4 miles in a straight line southeast of Silverton, just south of the road from Silverton to Hult post office and on the farm of Ai Porter. It is on the northeast side of the hill and slightly lower than the summit, 17 feet from a hne fence on the west, and 8 feet from another fence on the south. The surface and undergrountl marks at tliis station are crosses cut in the tops of one-half inch copper bolts embedded in bowlders, the underground mark being in a bowlder about 12 by 14 by 14 inches, with its top 1.9 feet below the surface mark, which is
in a bowlder about 14 by 18 by 24 inches, with its axis north and south. Two reference marks,
described in note 4,' are located as follows: One in a bowlder about 14 by 16 by 16 inches, set in the fence line 5.79 meters from the station in azimuth 108 55', and the other in a bowlder

about 14 by 16 by 24 inches, set in the fence line 7.125 meters from the station in azimuth

304 40'.

Barnes (Multnomah County, Oreg., O. B. F., 1903). On a cleared hUl about 4 miles west

of Portland, between the Barnes and Cornell roads, and just east of the highest hill in this range

which hUl is still densely wooded. It is on the south edge of the hill about 100 feet southeast of

a fir tree and some small maple trees, and close to the north side of a large stump. The station

is marked according to note 2,' the surface mark in a stone 8 by 14 by 18 inches with its top flush

with the surface of the ground, and the subsurface mark in a stone 6 by 12 by 18 inches IJ feet

below the surface mark. Two reference marks, described in note 4,' and set at the roots of

stumps on the sides facing the station are located as follows: One in a bowlder 15 inches in

diameter, distant 15.80 meters from the station in azimuth 1.56 11'; and the other in a bowlder

A 12 inches in diameter 7.02 meters from the station in azimuth 233 23'.

third reference mark

consists of a cross in the top of a bowlder 10 inches in diameter buried 15 inches beneath the surface and of a copper bolt directly above the cross, in a bowlder 14 by 14 by 18 inches set with its top flush with the surface of the ground. It is about 3 feet north of the main east-and-west fence line, about 30 feet east of where this fence crosses the highest part of the ridge, about 3 feet east of a fence extending northward from this fence and 44.95 meters from the station ia

azimuth 184 35'.

Larch (Multnomah County, Oreg., O. B. F., 1903). Southeast of Bridal Veil, a town on the Columbia River, on the highest peak of Larch Mountain and on the west point of a small rock ledge which is on the north end of a spur Irom the main summit. The ledge is about 20 feet higher than the spur of which it forms the end, and descends abruptly on the north in a cliff about 100 feet high. It can be reached either from Bridal Veil or Latourell via Donahue's
logging camp. The station is marked according to note 1.' Two reference marks, described in
note 4,' are in the east summit of the ledge, one in rather a low place 10.89 meters from the station in azimuth 298 51', and the other near the east end of the summit 15.01 meters from
m the station azimuth 287 02'.
Star (Clark County, Wash., J. S. H., 1906). On the most southerly of the two summits of Silver Star Mountain, on the line between Clark and Sl^amania Counties, about 35 mdes northeast of Vancouver. The station was marked according to note 3.* Two reference marks, described

77002 13 4

I See p. .

50

THE CALIFOBNIA-WASHINGTON ABC OF PBIMABY TRIANGULATION.

in note 4,' are at the following distances and azimuths from the station: 5.910 meters, 305 43';
and 5.160 meters, 26 11'. Davis (Cowlitz County, Wash., J. S. H., 1906). About 14 miles northeast of Woodland
on the highest j)oint of a hill on a north-and-south ridge which may be reached from Woodland by
following the road up the Lewis River to the Fisher place and packing from there. The station
is marked according to note 3.* Two reference marks, described in note 4,' are at the following
distances and azimuths from the station: 5.61 meters, 15 02'; and 5.37 meters, 96 51'.
Red (Skamania County, Wash., J. S. H., 1906). On the highest point of a bald, red hill
near the sources of the Little White Salmon and Lewis Rivers and not far from Klickitat Pass.
It is best reached from White Salmon on the Columbia River via Guler post office, Ice Cave, Peterson's prairie. Goose Lake, Steamboat Lake, and the Indian race track, being about 1 mile southwest from the last place and 1^ miles west of Steamboat Lake. The station is marked
according to note 3.' Two reference marks, described in note 4,' are at the following distances
and azimuths from the station: 7.400 meters, 96 14'; and 5.422 meters, 188 46'.
Warren (Columbia County, Oreg., O. B. F., 1903). ^About a mile southwest of Warren, a station on the Northern Pacific Railway, on a slight elevation or ridge near the west side of a
pasture owned by Mr. E. Hames and about 250 meters north of an east-and-west road. The
station is marked according to note 2,* the surface mark in a bowlder 8 by 24 by 24 inches with the letters "U. S." cut in the north side and the subsurface mark in a stone 6 by 12 by 18 inches
buried 18 inches below the ground. Three reference marks, described in note 4,' are in the
north-and-south fence line to the west of the station. The middle reference mark of the three
is 246.7 meters north of the north road fence and the other two are each about 30 meters distant
from the middle mark, one north and the other south. They are at the following distances and azimuths from the station: 23.67 meters, 93 15'; 37.46 meters, 41 26'; and 37.95 meters,
142 46'.
Lam (Cowlitz County, Wash., J. S. H., 1906). On the highest part of the heavily wooded
summit of Elk Mountain, about 35 miles northeast of Woodland. The station is marked accord-
ing to note 3.' Two reference marks, described in note 4,' are at the following distances and
azimuths from the station: 6.28 meters, 36 56'; and 10.84 meters, 319 02'. Len (Skamania County, Wash., J. S. H., 1906). In the northwestern part of Skamania
County, about 10 miles north of Mount St. Helens and a short distance northeast of Spirit Lake. Spirit Lake can be reached by stage road from Castle Rock via Toutle and St. Helens, and from the south landing on this lake the peak on which the station is located appears as a rocky summit through a gap almost due north. The station is marked according to note 3.' Two reference marks, described in note 4,* are at the following distances and azimuths from the station: 3.260 meters, 215 15'; and 12.220 meters, 138 04'.
Toutle (Cowlitz County, Wash., O. B. F., 1905). On the top of a conical hill, the highest
point of a long ridge, known locally as Gum Mountain, between the north and south forks of the
Toutle River and about 20 miles east of Castle Rock. The summit was heavily timbered in 1905 and lines of sight were cleared. The station is reached from Castle Rock via Toutle and St. Helens and the main road left at a point about 2}4 miles east of St. Helens at Muniker's place, from where the station is about 3 miles distant in a southerly direction. The station is marked according to note 2,' the underground mark in a stone 12 inches in diameter 2 feet below the groimd and the surface mark in a bowlder 12 by 18 by 24 inches. The reference marks are cop])er bolts set in the center of triangular blazes on each of three stumps on the sides facing the station, the first being 9.24 meters from the station in azimuth 104 22', the second 9.13
meters, in azimuth 165 16', and the third 7.90 meters, in azimuth 345 34'. Two blazed trees
are at the following distances and azimuths from the station: 18.24 meters, 162 52'; and 26.44
meters, 257 50'.
Huck (Lewis County, Wash., O. B. F., 1905). On a high, bald summit, known locally as
Huckleberry Mountain, and about S miles northwest of the highest point of the Deschutes
' See p. 43.

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATJON.

51

Mountains in this region. The station is on a level place on the summit and about 60 feet north of a sharp rocky point of about the same height. The station is marked by a one-half

inch drill hole 1 inch deep in the top of a bowlder 8 by 8 by 10 inches set flush with the surface

of the gp-ound. The reference marks, three in number, are similar drill holes in soUd ledges

along the west side of the ridge a Uttle below its top, and at the following distances and azimuths

from the station: 13.65 meters, 40; 7.30 meters, 60; and 5.60 meters, 136.

Bel (Pierce County, Wash., O. B. F., 1905). On a high rocky peak known as "Bel Jacket,"

about 10 or 12 miles a little south of west of Mount Tacoma, and about 9}4 miles by road from

Ashford. From Ashford there is a wagon road leading to Messler's place about 5 miles distant,

then a trail in the direction of Bald Rock ana Eagle Rock, which leads to a small lake from where

the peak may be seen about one-half mile distant a little to the west of north. The station is

marked according to note 3.' Three reference marks, described in note 4,' are at the following

distances and azimuths from the station: 7.26 meters, 328 46'; 5.24 meters, 16 22'; and 5.94

A meters, 188 29'.

driU hole is 16.89 meters from the station in azimuth 15 01'.

Hal (Lewis County, Wash., O. B. F., 1905). On the highest point of the most western one

of the high, bald summits of the Deschutes Mountains near the northern line of Lewis County

and due south of Tacoma. From the north the mountain appears as a symmetrical cone and

is best approached from Yehn, a town on the Northern Pacific Railway, via Peter Stone's ranch,

which is about 14 miles southeast of Yelm and a short distance north of the station. The station

is near the south point of the hilltop and marked according to note 3.' Three reference marks, described in note 4,' are located as follows: The first in a large bowlder, 10.55 meters from the station in azimuth 166 24', the second in a broad sloping ledge 4.81 meters distant in azimuth

333 35', and the third in about the highest point of rocks 2.71 meters distant in azimuth 13 07'. Rain (Thurston County, Wash., O. B. F., 1905). About 10 meters northwest of the

highest point of a prominent high hill about 4 miles south-southeast of the town of Rainier, about 1,200 feet above it, and just visible over the top of the timber from the town. It is prob-
ably in sec. 33, T. 16, R. 1 E., and it is about a mUe west-northwest of the ranch on the top of the ridge owned by N. N. Bungard. The station is marked according to note 2,^ the subsurface mark in a bowlder about 10 by 12 by 12 inches and 15 inches below the surface of the ground, and the surface mark in a bowlder 12 by 20 by 20 inches. Two reference marks, described in note 4,' are located as follows: One in a large bowlder at the highest part of the hiU, 8.75 meters from the station in azimuth 8 54', and the other in a bowlder at some distance down the slope
of the liill and 13.78 meters from the station in azimuth 218 42'.

Hurst (Pierce County, Wash., O. B. F., 1905). ^Near the north end and highest part of the timbered hill about 400 meters slightly south of west from the railroad station at Hillhurst, a town on the Northern Pacific Railway, and about one-half mile southwest of the store and post office. The hill is across the road south from the Cottage Grove farm, owned by Mr. Bucholtz. The station is marked at the surface with an old-type station mark, described on page 42, set in a concrete block 12 inches square and 18 inches deep, and underground by a one-half inch copper bolt 4 inches long set in the solid ground or native cement 3 feet beneath the surface. There are two reference marks, one of which is a copper bolt set in the only large rock in the neighborhood, 40.34 meters from the station in azimuth 252 40', and the other is a similar copper bolt in a bowlder 10 by 12 by 12 inches flush with the surface of the ground, with a smaller bowlder 8 by 10 by 10 inches directly below it, and is 13.52 meters from the station in

azimuth 150 41'.

Pen (Pierce County, Wash., O. B. F., 1905). About one-half mile south of Graham, a station on the Tacoma Eastern Railroad, about one-half mile northwest of Mr. Hansen's house, and 75 or 100 meters to the westward of the highest part of a flat, partly cleared summit. The

station is marked according to note 2.' Three reference marks, described in note 4,' are at tlie following distances and azimuths from the station: 18.93 ineters, 242 50'; 17.80 meters, 37 58'; and 23.15 meters, 160 53'.

> Seep. 43.

52

THE CALIFOBNIA-WASHINGTON ARC OF PBIMABY TBIANGULATION.

Tacoma south base (Pierce County, Wash., O. B. F., 1905). About 10 miles south of

Tacoma and 2 miles south of Spanaway Lake, on land belonging to William Sekor, in the prolonga-

tion of Pacific Avenue of Tacoma. From the top of the hill in South Tacoma this street is

nearly a straight line and Tacoma base line lies along it. The station is on the highest bench

near the south side of Sekor's property and near the highest point of the bench, being about 10

feet west of a small but prominent knoll. It is 178.5 meters from the fence on the south side of the field and 154.8 meters from the fence on the west side. The station is marked underground

by a cross in the head of a one-half inch copper bolt 3 inches long set in a block of concrete 2 J

feet square and 6 inches thick 3 feet beneath the surface, and at the surface by an old-type

station mark, described on page 42, set in the top of a concrete cube 2 J feet on an edge which

has a 4-inch drain tile 2 feet long at tlie center with its top flush with the surface of the con-

crete. There are tliree reference marks, each consisting of a copper bolt set in a concrete block

18 inches square an<l 6 inches thick buried 3 feet below the surface, and of a similar bolt above

it in a concrete block 18 inches square and 30 inches deep, its top 2 inches below the surface of

the ground. They are at the following distances and azimuths from the station: 49.658 meters,

263 50'; 38.938 meters, 347 25'; and 61.153 meters, 173 25'.
Tacoma north base (Pierce County, Wash., O. B. F., 1905). On Fern HUl, 4 miles south of

Tacoma and about one-fourth mile north of the crossing of Pacific Avenue and the Puyallup

Electric Railway. It is on a prominent knoll just south of the house owned and occupied by

H. A. Wilhelmi, 8.5 meters south of his south line and 19 meters east of the east line of Pacific

Avenue. The subsurface mark at the station is a cross in the head of a one-half inch copper bolt

3 inches long set in a block of concrete 30 by 30 inches and 6 inches thick, 3 feet beneath the

surface. The surface mark is an old-type station mark, described on page 42, set in a concrete

cube 2^ feet on an edge which has a 4-inch drain tile 2 feet long at the center with its top flush

with the surface of tlie concrete. There are three reference marks, each consisting of a one-

eighth inch copper wire embedded in an underground block of concrete 14 by 14 inches and 6

inches thick set 3 feet below the surface, and of a surface mark consisting of a similar

wire in a block 14 by 14 by 30 inches set with the top flush with the surface of the ground.

They are located as follows: The first, just north of Dr. Rynning's north fence and 4 feet east of

the east line of Pacific Avenue, 92.325 meters from the station in azimuth 10 19'; the second,

south of the back part of WUhelmi's house and just south of his south fence, 47.757 meters from

the station in azimuth 259 51'; and the third just south of Wilhelmi's south fence and 2 feet

east of the east line of Pacific Avenue, 19.672 meters from the station in azimuth 117 04'.
Bum (Pierce County, Wash., O. B. F., 1905). On a prominent ridge 2 or 3 utiles south-

west of the central part of the city of Tacoma, west of that part of the valley which is traversed

by the Northern Pacific Railway in an east-and-west direction and almost in line with the

east-and-west portion of the track, about three-fourths of a mile from its western end. It is

on a summit about one-half mile west of a prominent schoolhouse, about 300 meters southeast

of a house, and about 30 meters north of a private road leading from the house to the school-

house. The station is marked according to note 2,' with the subsurface bowlder about 2 feet

below the surface. Three reference marks, described in note 4,' are located as follows: The

first near a trail along the ridge and 23.53 meters from the station, in azimuth 160 44'; the

second on the north edge of the road 25.13 meters distant, in azimuth 320 00'; and the third

near the beginning of a slope 25.47 meters distant, in azimuth 85 34'.
Kin (Pierce County, Wash., O. B. F., 1905). On the top of a prominent hill in the south-

eastern part of Tacoma, just south of McKinley Park, in the block between Thirty-second

K Street and Wright Avenue and

and L Streets and very nearly halfway between Thirty-

second Street and Wright Avenue. It is directly in line with the gable ends of the N. P. B. A.

Hospital, a large brick building a couple of hundred yards to the westward of the station. The
station is marketl according to note 2.' Two reference marks, described in note 4,' are at the

following distances and azimutlis from the station: 24.55 meters, 215 48'; and 18.47 meters,

294 50'.

> See p. 43.

THE CALIFOKNIA-WASHINGTON ABC OF PKIMABY TBUNGULATION.

53

Wash (Pierce County, Wash., O. B. F., 1905). In the northwestern part of Tacoma, near the middle of Twenty-fifth Street and about 5 yards east of the east Hne of Washington Street projected across Twenty-fifth Street at their intersection. The station is marked by an old-type station mark, described on page 42, in a bowlder 18 by 24 by 30 inches, which is
buried with its top about 5 inches below the surface of the ground. Two reference marks,
each consisting of a punch mark in the head of a copper slug in a stone 2 feet below the surface and of a similar slug in a stone directly above the lower mark and about 3 inches beneath the surface, are located as follows: One at the northeast intersection of Twenty-fifth and Washington Streets, about 1^ feet east of the east line of Washington Street, 1 foot north of the north line of Twenty-fifth Street and 9.634 meters from the station, in azimuth 153 20'; and the other at the southeast intersection of the same streets, about 3 feet from Washington Street, 1 foot south of the south line of Twenty-fifth Street and 17.713 meters from the station, in
azimuth 12 22'.
Bos (Pierce County, Wash., O. B. F., 1905). In the flat about 2 miles east of Tacoma and one-third of a mile south of the trestle leading from the city across the marsh to the mills
on the east side of the valley. It is about 75 meters northeast of a small white house at the north end of the strip of fast land which extends farthest into the marsh and on a very slight elevation, clear of trees and buildings, on the edge of a slough. The station is marked according to note 2,' the lower mark in a small bowlder 15 inches below the surface and the upper mark in a bowlder about 10 inches in diameter projecting 3 inches above the surface of the ground. There are no reference marks, but a broken-topped fir tree is about 60 meters from the station, in azimuth 331 44', and the west comer of the small white house is 77.72 meters
distant, in azimuth 13 54'.
GuU (King County, Wash., J. J. G., 1891; 1905). On Commencement Bay, north of Tacoma, and about 1 mile southeast from Brown Point Lighthouse, on the bold bluff about 125 feet high, which is conspicuous on approaching the point from Tacoma. The station is
about 15 feet from the edge of the bluff and in range with the tower of the Lowell School in
Tacoma and the left tangent of the tall, dark, cylindrical building with a dome roof, which belongs to the Tacoma Lumber Co.'s mill, and bears about southwest from the station. The station is marked by a bottle buried 2^ feet below the surface and by a nail in a pine stub at
the surface of the ground.
Dron (King County, Wash., O. B. F., 1905). On Commencement Bay, about one-half mile southeast of Brown Point Lighthouse and about one-half mile west of station Gull. It is
on the highest part of a bluff point about 60 feet above the water and 20 or 25 feet inland from the edge of the bluff, in a thicket of madrona trees, some of which were felled to clear the line
to station NeiU. The station is marked according to note 2} Two reference marks, described
in note 4,' are at the following distances and azimuths from the station: 4.42 meters, 175 08'; and 5.01 meters 308 03'.
Smelt (Pierce County, Wash., O. B. F., 1905). On a ridge in the extreme northwestern part of Tacoma just south of Point Defiance Park. To reach the station foUow the electric line, which runs to the smelter, to a point about 300 yards beyond where the cars make the last turn at
Highland Park, and there take the road which leads toward the west, following it until the top
of the ridge is reached. From there keep along the ridge toward the north until the Brown
Point lighthouse and the left tangent to the second smelter chimney to the north of the 300-foot smelter stack are in range, then follow this range to within 5 or 10 yards of the edge of the plateau. The station is not far from the west end of the main ridge, considerably below the highest point, and at about the same elevation as a small knoll some 300 feet to the west. The station is marked according to note 2,' except that the subsurface mark is a one-haK inch drill hole in a stone 18 inches below the surface. The surface mark is in a bowlder 10 by 18 by 18 inches set flush with the surface of the ground. One reference mark consists of punch holes in the heads of copper slugs set in each of two stones, one 15 inches underground and the other at
1 See p. 43.

54

THE CALIFORNIA-WASHINGTON ABC OP PBIMABY TBIANGULATION.

the surface, 28.55 meters from the station in azimuth 27 38'. The other reference mark is a

copper slug set in a stone in place 53.16 meters from the station in azimuth 236 33'.
NeUl 2 (Pierce County, Wash., O. B. F., 1905). On Neill Point at the southeast end of

Vashon Island, about 6 or 8 feet above high-water mark and 15 feet inland from it. The station

is marked only by a tack in the top of a pine stub.

A Tacoma astronomic station (Pierce County, Wash., J. F. P., 1892; 1905).

stone pier

A near the north end of Wrights Park, Tacoma.

brick pier 17 inches square and 5i feet long,

used for latitude observations in 1894, is 12 feet 3 inches due east of the station.

StJPPLEMENTAKY POINTS.

Coming tower (Tehama County, Cal., O. B. F., 1904). The tower at the south end of the Maywood Colonization Building, a wood and plaster structure, just across the street from the

Maywood Hotel and southwest from the railroad station. Comijig astronomic station (Tehama County, Cal., W. H. B., 1908). On the vacant lot just
west of the Maywood Colonization Building at Coming. (See Coining tower, above.) The

station is not marked but the following distances and azimuths to different parts of the Maywood

Colonization Building were measured.

Tower, 23.40 meters, 247

24'.2 northwest comer of the ;

porch-like part of the building known as the Arcade, 31.40 meters, 207 55'.2-, and southwest

corner of the same Arcade, 16.64 meters, 242 17'.8.

Redding courthouse (Shasta County, Cal., O. B. F., 1904; 1908). The center of the top of

the dome of the courthouse upon which stands the statue of justice. The statue is eccentric to

A the center of the dome by about 1 ^ feet.

triangle with a small hole at the center is cut in the

floor of the dome directly below the center of the dome and may be used as the station.

Redding astronomic station (Shasta County, Cal., O. B. F., 1904; 1908). On a prominent

hill about three-fourths of a mile south by west from the railroad station at Redding. To reach

the station follow the railroad track south to milepost 259, which is marked at present by a board

nailed to a telegraph pole, where will be found a United States Geological Survey bench mark, a

metal tube with a brass top, and from here the station is west about one-fourth of a mile. The

station is on the brow of a hill somewhat toward the south edge and not quite at the highest

A point.

live oak about 6 inches in diameter is on the edge of the hiU just north of the line to

the Geological Survey bench mark and a leaning pine tree about a quarter of a mile distant is in

Ime with the Redding courthouse. The station is marked according to note 1,' in the top of a

large bowlder projectmg 4 inches above the ground. Two reference marks, described in note

4,' are at the following distances and azimuths from the station: 20.22 meters, 115

49' and 9.99 ;

meters, 188 17'.
Redding south base (Shasta County, Cal., W. H. B., 1908). About 15 feet east of the rail-
road track at Redding and opposite a large steel oil tank. The station is marked oidy hj a

nail in the top of a wooden stub and by the three instrument stubs.
Redding north base (Shasta Count}', Cal., W. H. B., 1908) . Near the northwest corner of the
cemetery south of the railroad station at Redding and about 15 feet east of the track. The station is marked oidy by a nail in a wooden stub and by the three instrument stubs around it.
Hill (Shasta County, Cal., W. H. B., 1908). On the east brow of a ridge just north of the

ridge on which Redding astronomic station is located (see above), and almost on the line between that station and the courthoiwe at Redding. The station is marked only by a wooden stub

and the three instrument stubs surrounding it.

Central Point astronomic station (Jackson County, Oreg., O. B. F., 1904; 1908). About 2

miles north of Central Point, near the intersection of the Southern Pacific Railway and the

county road and in the northwest comer of the field which is just east of the county road and south of the private road leading to the house occupied by George Mims. The station is about 30 meters from the railroad. (See Central Point latitude station, below). The under-

ground mark at the station is a three-fourths inch drill hole in the top of a triangular granite

> See p. 43.

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

55

rock, set in cement 15 inches below the surface of the ground. The surface mark is an old-type station mark, described on page 42, set in the top of a granite rock which projects 2 inches above the surface and which is embedded in a mass of concrete 30 inches square and 12 inches deep. The reference mark, a United States Geological Survey bench mark, is at the intersection of the railroad and the county road, just east of the rail on the east side of the road and 28.15 meters from the station in azimuth 31 55'.
Central Point latitude station (Jackson County, Oreg., W. H. B., 1908). Near Central Point astr&nomic station (see above) and marked only by a wooden pier: The fbllowing distances and
azimuths were measured: Astronomic station, 4.77 meters, 116 41'; United States Geological
Survey bench mark (reference mark of astronomic station), 28.82 meters, 41 18'. The north and west fences of the field are, respectively, 6.18 meters and 15.55 meters from the station.
Rose (Douglas County, Oreg., O. B. F., 1904). On the highest point of the highest bald
summit of a ridge about IJ miles north of Roseburg. The station is marked according to note 2,' the underground mark in a mass of concrete 1 foot below the surface and the surface mark
in a bowlder 9 by 14 b}- 18 inches flush with the surface of the ground. Two reference marks,
described in note 4,' are at the following distances and azimuths from the station: 16.71 meters, 12 24'; and 7.49 meters, 125 23'.
Burg (Douglas County, Oreg., O. B. F., 1904). On a high, bald summit about 3 miles
southeast of Roseburg. As seen from the iron bridge over the river just west of the railroad station, it is the highest and most distant peak visible up a small valley. The station is marked according to note 2,' the underground mark in a mass of concrete 13 inches below the surface, and the surface mark in a bowlder 10 by 12 bj' 14 inches set flush with the surface of the ground. The reference mark, described in note 4,' is in a bowlder just over the edge of the hill, 10.24 meters from the station in azimuth 112 45'.
Roseburg latitude station (Douglas County, Oreg., O. B. F., 1904). On the point of a spur
across the river from the town of Roseburg, about 100 feet west from the end of the bridge
and 60 feet above it. The station is marked according to note 1,' set in a ledge of rock. Two reference marks, described in note 4,' are located as follows: One in a prominent ledge 18.18
meters from the station in azimuth 30 17', and tlie other in the side of a ledge flush with the ground, 32.30 meters from the station in azimuth 109 05'.
Springfield Methodist Church (Lane County, Oreg., W. H. B., 1908). ^The lower and less
prominent of the two churches at Springfield.
Springfield Christian Church (Lane County, Oreg., W. H. B., 1908). The taller and more
prominent of the two churches at Springfield.
Deady Hall, west tower (Lane County, Oreg., W. H. B., 1908). Deady Hall is one of the two
larger buildings of the University of Oregon at Eugene and has large square towers at both the east and west ends.
Geary School spire, Eugene (Lane County, Oreg., W. H. B., 1908). The Geary School is the pubUc school located at West Fourth and Madison Streets, Eugene.
United Brethren Church spire, Eugene (Lane County, Oreg.,- W. H. B., 1908). At East
Eleventh and Ferry Streets, Eugene.
Patterson School spire, Eugene (Lane County, Oreg., W. H. B., 1908). ^The public school located one block west of the southwest comer of the campus of the University of Oregon, at
Eugene.
Baptist Church spire, Eugene (Lane County, Oreg., W. H. B., 1908). At East Eighth and
Pearl Streets, Eugene.
W. 0. W. Hall spire, Eugene (Lane County, Oreg., W. H. B., 1908). The old Episcopal Church located at West Eighth and Lincoln Streets, Eugene, which is now being used as a hall by the Woodmen of tlie World.
Courthouse flagpole (Lane County, Oreg., W. H. B., 1908). At East Eighth and Oak
Streets, Eugene.
' See p. 43.

56

THE CALIFORNU-WASHINGTON ABC OF PRIMABY TBIANGULATIOX.

Methodist Church spire (Lane County, Oreg., W. H. B., 1908). The Humphrey Memorial

M. E. Church located at West Tenth and Willamette Streets, Eugene.

Seavies ( V. S. G. S.) (Lane County, Oreg., O. B. F., 1904). Tliis station is identical with

the United States Geological Survey station of the same name. It is on the most southern of

the high liills, about 6 miles northeast of Eugene and about 30 or 40 feet southwest of and sliglitly

lower than the highest part of the hill. The station is marked by a square stone 4 by 4 by 24

inches with its top a Uttle below the surface. The old Geological Survey signal was still standing

in 1904, anchored in place by rocks, and was not disturbed.

Monument, General Land Survey (Multnomah County, Oreg., O. B. F., 1903). The initial

intersection of the First Standard Parallel and the Willamette Meridian, a short distance

southeast of Barnes. (See p. 49.) The station is in a fence comer and is marked by a stone

post projecting 1^ feet above the ground.

River (Multnomali County, Oreg., O. B. F., 1903). Near the junction of the two suburbs

of Portland known as Arbor Lodge and Peninsula, on the east bank of the Willamette River

about a mile east of Columbia University. It is on a slight elevation, the highest in the vicinity,

and in the fence line on the north side of the boulevard along the river bank. It was placed

as far east as possible and still keep the Oregonian Building in view. The station is marked by

crosses cut in the tops of two bowlders, one placed near the surface of the ground and the other

directly

beneath

at

a

depth

of

1.7

feet,

each

stone

bearing

the

letters

"U.

S.

C.

" S.

cut

in

the

top.
Oregonian (Multnomah County, Oreg., O. B. F., 1903). The tall iron pole at the southeast comer of the tower of the Oregonian Building at the northwest comer of Sixth and Adler
Streets, Portland.
Portland longitude station (Multnomah County, Oreg., C. H. S., 1887; 1905). This station
has been destroyed. Portland latitude station (Multnomah County, Oreg., C. H. S., 1887; 1905). This station
has been destroyed.
Rocky Butte (Multnomah County, Oreg., C. R., 1889; 1903). On the north side of the
highest part of the brush-covered summit of the butte, about 2 miles northeast of Montavilla. The station is marked by a hole drilled in a large round-topped bowlder.
Harney (Clarke County, Wash., C. R., 1881; 1903). On the north bank of the Columbia
River, about 1^ miles above the United States wharf at Vancouver, on the sloping bare bluff iimnediately above the road leading from Vancouver up the river. It is almost in front of the "Harney House," on land formerly owned by Gen. Harney, and about 80 meters east of the fence inclosing the race track. The underground mark consists of a glass bottle placed 3 feet below the surface, with the neck up, the center of the neck marking the station, and three other bottles placed on their sides at a depth of about 1 foot and at distances of about 6 feet from the center, with the necks of the bottles pointing toward the center. The surface mark
is a small drill hole 2 inches deep in a basaltic bowlder, weighing about 350 pounds, placed with its top flush with the surface of the ground. The following bearings to the right of magnetic north were read at the station: East chimney of Harney House, 27 05'; triangle on tree 74 28'; wliite house on south side of river, 172 55'; ventilator on bam, 220 06'; and comer
of race track fence, 276 47'.
Batch (Multnomah County, Oreg., C. R., 1881; 1906). This station was occupied for azimuth in 1886. It is immediately northwest of the city limits of Portland, about a mile south of the Willamette River, on the first small level bench of the spur making out from the ridge west of the Cornell road, and about 255 feet above the road. The station is marked imderground by a broken-necked bottle placed neck up 2 feet below the surface, and by a cross in the toj) of a copper bolt set in concrete 6 inches above the bottle, and at the surface by a cross on an old-type station mark described on page 42, set in concrete, which is inscribed with the letters
& "C. G. S." The reference marks are the remains of two brick piers built in line to the
west of the station, with their foundation about 20 inches below the surface, the nearest edge of the first pier being about 1 meter west of the station.

THE CALIFORNIA-WASHINGTON AEC OF PRIMARY TRIANGULATION.

67

Dash (King County, Wash., G. D., 1857; 1905). On the sand spit called Dash Point,

about 1 mile northeast of Brown Point Lighthouse and 10 or 12 feet back from the high-water

mark. The station is inclosed within a wall of old timbers to protect it from the washing of

the waves, and is marked by a one-half inch drill hole 2 inches deep in a stone buried a foot

beneatii the surface. Two reference marks, probably drill holes in bowlders, are at the follow-

ing distances and azimuths from the station: 18.05 meters, 284 34'; and 37.32 meters, 352

A 21'.

blazed fir tree is about 60 meters distant in azimuth 324 41'.

Finer 2 (King County, Wash., O. B. F., 1905). On the southeast point of Maury Island,

A about 25 feet above high tide and 30 or 40 feet inland from high-water mark.

group of four

])iles is 30 or 40 meters east of the station, and a large rock, the largest in the vicinity, is in the

water 50 or 60 meters south and a little west from the station. The station is marked by a

three-fourths inch drill hole in a large stone set flush with the surface, and underground by a

similar drill hole in a stone 2 feet below the surface of the ground. Two reference marks, each

consisting of surface and subsurface stones, are at the following distances and azimuths from

the station: 4.61 meters, 86 55'; and 4.65 meters, 167 45'.

Robinson 2 (King County, Wash., J. S. L., 1867; 1905). On Robinson Point, on Maury

Island, about 300 meters southwest of the scaffold light, on a bluff about 20 feet above high

tide and 30 feet inland from high-water mark. The station is 95 meters southwest of the light

keeper's dwelling, 42 meters southwest from the southeast comer of the light keeper's shed or

bam, and about 2 meters west of the fence which extends southwest from the comer of the

A shed.

large madrona tree at the top of the bluff is 15 or 20 meters southwest of the station.

The station is marked underground by a one-half inch drill hole in a stone buried 1 foot deep

and at the surface by a similar hole in a stone, directly above the lower mark, set with its top

flush with the surface of the ground. One reference mark is a one-half inch drill hole in a, solid

stone which is in line with the fence ninning southwest from the shed, and is 2.93 meters from the station in azimuth 26 25'. The other reference mark consists of surface and subsurface

stones, the lower one 1^ feet beneath the surface, and is 10.62 meters from the station in

azimuth 185 06'.

COMPUTATION, ADJUSTMENT, AND ACCURACY OF THE ELEVATIONS.
The zenith distances directly observed at each station were first computed. These zenith distances were corrected for height of the object observed and of instrument so as to refer them all to the ground at each station or to the station marks.
The difference of elevation of each pair of stations in the main scheme was then computed from the observations over the line joining them by the formula

\~\ = sifm

Vi

+ (C2-c.)[i+^^' y|^]

in which h^ and /t, are elevations of the stations, (^^ and ^j are the measured zenith distances as corrected for height of instrument and of object observed, s is the horizontal distance between the stations, and p is the radius of curvature.
As there are always two or more lines to each new station, many rigid conditions exist
between the observed difference of elevation, even if the connections with the precise leveling were ignored, and the least square adjustment furnishes the readiest accurate means of deriving the required elevations.
The elevations of the primary scheme throughout the arc from the stations of the Thirtyninth Parallel triangulation to Puget Sound were adjusted in three sets of equations.
The first adjustment involved all stations of the primary scheme from the Thirty-ninth
Parallel to the Willamette base.
The second adjustment fixed the elevations of the primary stations connecting the Tacoma base with the Puget Sound triangulation.

58

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

The third adjustment fixed the elevations of the primary stations between the Willamette base net and the Tacoma base as well as the secondary stations connecting these with the Columbia River.
In the first adjustment the elevations of stations Redding astronomic, Gazelle astronomic, Central Point astronomic, and Roseburg latitude were held fixed at 202.16, 848.28, 369.92, and 165.24 meters, respectively. These elevations were determined directly from the leveling of the United States Geological Survey. The precise leveling over the base and over a side line 1 kilometer in length connected the terminal marks of the Willamette base with the bench mark 4 miles north of Irving, also established in 1903 by the United States Geological Survey. The elevation published for this bench mark ' was increased by 0.286 foot (0.087 meter) and the elevations 101.36 and 116.59 meters adopted for the Willamette north base and south
base, respectively.
The elevations of Mount Helena and Snow Mountain West were held fixed by the adjustment published in Special Publication No. 4, page 279, as 1322.08 and 2145.66 meters, respectively. The zenith distances measured at these stations in 1876 and 1892 were used to fix the elevations of Snow Mountain East and Marysville Butte. They were first changed by eliminating all observations made near sunrise and sunset, as these have been proved unreliable. They were then treated as reciprocal observations in connection with the zenith distances measured in 1904 at the latter stations. The elevation of Snow Mountain East was
held fixed at 2,150.56 meters as determined directly from Snow Mountain West, a line only 923
meters in length.
The elevations of the 26 remaining stations connected by the observations are unknowns, to be determined by least squares from the 82 observed differences of elevation indicated below.
In the following tabulation there are shown the observed differences of elevation treated in the first adjustment, together with their adjusted values. The weight p assigned to each
observed difference of elevation is inversely proportional to the square of the length s of the
line between stations in meters and was conveniently computed by the formula log />=10 2 log s. The observed difference of elevation is given the sign of the elevation of the second station named minus the elevation of the first. The quantity contained in the last column but one is the correction to be added to an observed difference of elevatiofi to obtain the adjusted
difference of elevation.

Adjustment of elevations Thirty-ninth Parallel to WUlamette base.

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

59

Adjustment of elevations Thirty-ninth Parallel to Willamette hase Continued.

60

THE CAUF0RNIA-WA8HIN0T0N ARC OF PRIMARY TRIANGULATION.

The probable error of an observation of weight unity derived from the preceding adjustment is 1.08 meters. In other words, the reciprocal observations over a line 31.7 kilometers
(19 miles) long,' this being the length of line corresponding to unit weight, determined the difference of elevation of two pouits with such a degree of accuracy that it is an even chance whether the error is greater or less than 1.08 meters.
This probable error is unfair because of the fact that observations at the stations Roman
and Spencer in June and July, 1903, were used in connection with those at Yellow and Fairview in October, 1904. The necessary assumption that the refraction is the same in the reciprocal observations was undoubtedly wrong in this case. The reason the four lines were retained in
the adjustment was to connect the elevations of the two seasops. A rejection of the two lines,
Yellow-Spencer and Yellow-Wliite, reduces the probable error of an observation of unit weight from 1 .08 to 0.77 meter. The latter is believed to represent more faithfully the value of the vertical angle results in this work.
The probable errors for hnes of other than unit length were assumed to be proportional to
their lengths.
The probable errors of the elevations of the six stations fixed by the spirit leveling done by the United States Geological Survey are doubtless well within 0.3 meter. The probable error approaclies this value for stations adjacent to those fixed by the leveling and is greatest for tlie most remote stations. The probable error of the elevation of Mount Helena was computed as 0.62 meter and of Snow Mountain West as 1.14 meters.^ Snow Mountain West
may be considered as the least accurately determined and this probable error, derived from the old work, 1.14 meters, may be assumed to be as large as for any station in the entire arc.
The new elevation here computed for Marysville Butte, 638.0 meters, very properly supersedes that published on page 312 of Special Publication No. 4, which was determined solely from nonreciprocal observ^ations from which the early morning and late evening observations were not eliminated.
The elevations of the stations of the main scheme from the Tacoma base to the connection
with the Puget Sound triangulation were obtained from the second adjustment as shown in the tabulation below. The elevation of Tacoma City Hall, a bench mark of the United States Geological Survey, was held fixed at 33.518 meters, a publishetl elevation derived from tidal observations by this Survey. In addition to this the observed difference of elevation, 1.93 meters, between Tacoma north base and south base was superseded by the difference of elevation, 2.13 meters, from the precise levels run over the base line by the party measuring the
base.
There is, then, in this section one fixed elevation and one fixed difference of elevation. The elevations of the 13 remaining stations connected by the observations are the unknowns to be determined by least squares from the 34 differences of elevation indicated in the following tabulation. They are shown in the same form used for the first adjustment, except that the
weight p assigned to each difference of elevation was computed by the fonnula log p = 9 2 log s.
This Is the usual unit weight. A weight ten times as largo was used in the above table.
"See p. 279, U. S. Coast and Geodetic Survey Special Publication No. 4.

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

61

Adjustment of elevations. Puget Sound to Tacoma base.

62

THE CALIFORNIA-WASHINGTON ABC OP PRIMARY TRIAXGUI-ATION.

Adjustment of elevations Willamette base net to Tacoma hose.

THE CALIFORNIA-WASHINGTON ABC OF PRIMARY TRIANGULATION.

63

ELEVATION OF MOUNT SHASTA.

One of the results of the vertical angle adjustments was a new elevation of Mount Shasta.

This elevation was computed from reciprocal observations over six hnes varying from 38 to 97

kilometers in length. The first computation was made using a mean value of the coefficient, m,

A of 0.066, and the results had a range of 14.6 meters.

final computation was made using the

value for the coefficient of refraction which was a mean of the values computed from the Unes

radiating from the observing station, but corrected for the mean elevation of the line. The

following are the values for the height of Mount Shasta :

From Round From Bally FromMears From Boliver From Sterling From Soda

1043. 36+3272. 69=4316. 05 1892. 35+2424. 21=4316. 56 2174.00+2142.55=4316.55
2451. 45+ 1867. 28=4318. 73
2239. 03+2070. 00=4309. 03 1857. 11+2558. 37=4315. 48

p=2.
1.1 6.9 3. 7 1.3 1. 7

Weighted mean

4316. 5 meters (or 14162 feet).

ACCURACY OF VERTICAL ANGLE RESULTS IN THE UNITED STATES.

In the following table 25 sections of vertical angle results of triangulation in the United States having separate least square adjustments have been arranged in order of accuracy, the most accurate being placed first. The best test of accuracy is beheved to be the probable error of an observation of unit weight. Such an observation is here considered as the reciprocal nonsimultaneous observations over the length of line corresponding to unit weight, considered as
.31.7 kilometers (19 miles).

Sections of triangulation in order of accuracy.

Section

64

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TBIANGULATION.

It has been declared to be "useless to aim at a high degree of accuracy in vertical measures since the irr^^lar variation of the refraction from hour to hour and day to day produces changes_ in vertical angles which affect the tens of seconds and sometimes even the mmutes."' Should not this declaration be modified ?

In considering the results in the above table it should be noted that the least accurate

groups are those of the Transcontinental Arc where the observations extended over a great many

days but at hours of the day when the refraction was great. The most accurate of the sections

are the ones of the Ninety-eighth Meridian where the observations were confined to the hours

nearest the time of minimum refraction, 11 a. m. to 3 p. m. The indiscriminate meaji of the

probable errors, excluding the two least accurate sections, is 0.68 meter or an uncertainty of

4". 43 in the zenith distance. Zenith distances, which are affected by unusual refraction to

the extent of "tens of seconds and sometimes minutes," would exceed 3^ times the probable

error and would be subject to rejection.

The sections where the lines are longest appear to have less accuracy, and this can be readily

accounted for by the effect of the differences in the station errors between the ends of the line

over which the zenith distances are observed. No effort has been made to correct the zenith

A distances for this difference in station errors.

second cause for the decrease in accuracy on

the long Unes^is the necessarily longer interval between the observations at the ends of these

lines allowing seasonal changes in the refraction to occur.

In conclusion, the results would indicate that the aim should be for a few accurate measures

of the zenith distances on more than one day and between 12 and 2 p. m. (or better, between 10

and 12 a. m. if the lines are near the coast), with no long interval of time between the observa-

tions at the two ends of a line. JSee pages 253 to 256 of Special Publication No. 4^,for a dis-
cussion of the times of maximum and minimum refraction at coast and interior stations.)

ELEVATIONS

The datum for all the elevations is mean sea level. The stations are ui three classes: First, those fixed directly by the spirit leveling, and of which the elevations are subject to a probable error varying from 0.15 to 0.3 meters; second, the stations in the main scheme fixed by reciprocal measures of vertical angles and which are subject to probable errors varymg from 0.2 to 1.1 meters, and, third, the mtersection stations, of which the elevations are fixed by measurements of vertical angles which are not reciprocal, the intersection stations not being occupied, and whose elevations are subject to probable errors which may be great as 3 meters in some cases. The accuracy with which each elevation in the main scheme is determined depends mainly upon the remoteness of that station from the nearest one of which the elevation is fixed by spirit levsling, as indicated in class 1 of the following table. Station Snow Mountam west is probably least accurately determined of all the stations in the main scheme. For a table to be used in converting feet to meters, or vice versa, see page 34.
TABLE OF ELEVATIONS
Thirty-ninth Parallel to Willamette base

.station

THE CALIFOBNIA-WASHINGTON ABC OF PRIMARY TRIANGULAXION.

66

TABLE OF ELEVATIONS Continued.

Thirty-ninth Parallel to Willamette lose Continued.

station

Point to wblcb elevation refers

Elevation

Class 2
Mount Helena Snow Mountain west Snow Mountain east
MaryBville Butte Kent
Lyons Bally Round
Spur Boliver Mears
Sterling
Soda Onion Rust White Black
Scott
Burg Rose Fairview Yellow
Roman
Spencer Mary Peterson
Twin
Ridge Rauch
CUmS
Lassen Peak Mount Linn Mount St. John
Bully Choop Crater Peak Saw Tooth Thompson Peak Russian Peak, north point Pilot Rock China Mountain Ashland Peak Marble Mountain Mount Eddy Mount Shasta Goose Nest Redding Courthouse
Little Shasta Black Butte Preston Peak
Greyback Siskiyou Wagner Kerby Mount Pitt Lost Peak Aspen Peak Mount Scott Liao Rock High Rock Union Peak Old Bailey Dodson (t. S. G. S.) Diamond Peak
Quartz
Mount Washington
77002 1.3-

Station mark
Top of pier Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark Station mark
Top Top Top Top Top Summit
Top Highest summit Summit Summit Summit Summit Summit
Top of peak
Tree-top Tangent to roof
Top of peak Top of cairn Top of peak Top of peak Top of peak Highest summit Top Summit
Top Top Top of peak Top Top Top Top Top of peak Top of peak Top of peak Top of peak

ifetert
1322. 1 2145. 7 2150.6
638.0 2032. 9 2031. 4 1892. 4 1043.4 2766. 9 2451. 5 2174. 1 2239. 3 1857. 4 1597. 1 1891. 2 1222. 7 1874. 1 1294. 6
608.7 453.3 1806. 3 746.3 872.3 626.2 1248. 8 437.2 389.8
36L0
202.2
3189. 9 2463. 8 2057. 6 2126. 8 2646.5 2717. 4 2555.0 2494. 3 1803. 9 2606.2 2296. 7 2533. 3 2754.8 4316. 3 2398. 5
198.2 2532. 9 1933. 8 2232. 2 2149. 5 2178. 4 2211.4 1689. 5 2893. 6 2446. 2 2502.0 2717. 7 2484. 1893. 8 2347. 9 2548.3
984.5 2679. 7 1686. 4 2368.

66

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TEIANGULATION.

TABLE OF ELEVATIONS Continued

Thirty-ninth Parallel to WiUiamette hose Continued

station

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

67

TABLE OF ELEVATIONS Continued

WiHamette hose net to Tacoma base Continued

station

68

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

o

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

69

No. 2.

i2?l

izoT

flFT

O m I N I N OF CANADA

Ifll

Index Map.

70

THE CALIFORNIA-WASHINGTON ABC OF PRIMARY TRIANGULATION.

I23T00'

No. 3.

THE CALIFORNIA-WASHINGTON AEC OF PBIMARY TRIANGULATION.

71

IZ3130'
Onion

IZ3iOO'

IZZ30'

122100

No. 4.

-+

'Mt.Pitt

ihlX

Herby
I
/
eston Peak

yi Goose Nest / ^^Little Shasta

-+

Pussian PeokMpoipt^^-'-Vj

^-'<^

'

'
HHi

Eddy

/I' '

Russian Peakspoint -^

'
tSCBoliver

-+
Lu

'
Sow ToothC^
\ Thompson Peak
\

"^'od Af30' itroo

72

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TBIANGULATION.

No. 5.

Onion-Kust to Mary-Peterson.

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

73

No. 6.

Mary-Petereon to Davis-Red.

74

THE CALIFORNU-WASHINGTON ABC OF PRIMABV TRIANGULATION.

No. 7.

Davis- Kcd to I'uget Sound.

Index to positions, descriptions. sTcetches, and elevations
station

Albany courthouse cupola Alsea Peak, partly cleared, wooded Bummit
Arquett, cairn Ashland Peak, cairn Aspen Peak Astronomic station :
Central Point ,

Coming

Eugene

,

Gazelle

Redding

,

Tacoma ,

Balch

Ball Butte

Ballj;
Baptist Church spire, Eugene Barnes

Bel

Bench mark, Portland

~.

Black

Black Butte, cairn

Boliver (Cal.) Bos

Brown Point Lighthouse

Bully Choop

Buig Btim

Cannibal Peak, highest wooded summit
Cem

Central Point astronomic station
Central Point latitude station
Chemawa tank
China Mountain (not the cairn) Christian Church spire, Springfield City Hall, Tacoma Coming astronomic station Coming tower Corv-allis, closed cupola
Corvallis, open cupola Courthouse :

Eugene, flagpole
Redding Tacoma, cupola Crater Peak Dash

Davis

Deady Hall, west tower, Ei^ene Deschutes Peak
Diaaiond Peak
Dodson(U. S.G. 8.) Dron

Eagle , cairn
Eugene: Astronomic station
Baptist Church spire Courthouse flagpole Deady Hall, west tower Geary School spire Methodist Church

Patterson School spire
United Brethren Church spire
W. O. W. Hall spire

76

THE CALIFORNIA-WASHINGTON ABC OF PBIMABY TRIANGULATION.

Index to positions, descriptions, sketches, and elevations Continued.

station

Fairdale Peak

Fairview

Fir

Forest Peak, tallest trees
Gazelle astronomic station
Geary Sch)l spire, Eugene Goat Mountain

Goovse Nest, tall tree

Greyback Gull

Hal.

Hamey

Hayrick
Herman Peak, wooded summil. .

High R(x;k(Oreg.) High Rock (Wash.)

Hill(Cal.)

Hill(Oreg.)

Huck

,

Hult

Hurst

Kent

Kerby Kin
Lam
Larch Lassen Peak
Latitude station : Central Point
Portland

Roseburg Lebanon, tall brick chimney Left Nipple Len Liao Rock
Little Shasta
Longitude station, Portland Lost Peak

Lyons

:

butrble Mountain

Marj' Marysville Butte Mears
Methodist Church:

Eugene

Springfield, spire
Middle Sister

Min

Mineral Peak

Mitchell

Monmouth Peak

Monument, General Land Survey Mount A6ams

Mount Eddy, cairn Mount Helena

Mount Hood

Mount Jefferson

Mount Linn

Mount Pitt

Mount Rainier, bare summit Mount Rainier, high peak Mount St. Helens

Mount St. John

,

Mount Scott

Mount Shasta, top of

,

Mount Washington

Mount Zion

Nebo

Neill2

Position Description

Sketch

Elevation

Ptfe 41 35 41 40 35 39 42 38 38 36 36 41 40 40 38 42 37 41 36 36 36 34 38 36 36 36 37
38 41 39 40 40 36 38 38 41 38 34 38 35 34 35
39 39 40 42 42 41 40 41 41 37 34 41 40 37 38 42 42 41 37 38 37 40 39 40 37

Pttft
46
45 55
53 51 56
54 50 49 51 44 52 50 49
55 56 55
50
56 44 46 43 44 56 55

Nuviber
6 5 6
,
6 4 5 7 4 4
7 7
6 5 5 5
7 3 6 7 6 7 3 4 7 7
6 3
4 6 5 6 5 7 5 4 6 4 3 4
5,6 3 4

56 43

54

Paje 66 65 66 66 64
67 65 65 67 66 66 66 66 65 67
66 66 66 67 65 65 67 66 66 65
64 66 66 66 65 65
65 65 65 65 65 65
66
67 67 66 66 66 65 65 66 66 65 65 67 67 67 65 65 65 65 66 66 67

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

77

Index to positions, descriptions, sketches, and elevations Continued.

station

North bSse;

Redding Tacoma
Willamette
North Sister
Old Bailey Onion

Oregonian Patterson School spire, Eugene Pen
Peterson
Pilot Rock
Piner2..,

Pisgah Portland:
Bench mark
Ijatitude station
Longitude station Prairie Peak, west tree Preston Peak

Quartz Rain
Ranch Red

Redding: Astronomic station
Courthouse
North base
South base
'
Ridge River Robinson 2
Rocky Butte Roman Rose
Roeeburg latitude station Round
Round Peak
Russian Church, crfiss Russian Peak, north point Russian Peak, south point Rust.
St. Mary Butte Salem Capitol, dome Saw Tooth
Scott
Seavies (U. S. G. S.) Sea vies 2
Sharp Peak Shendan Peak, highest green tree
Siskiyou Smelt
Smelter stack, 300 feet high
Snow Mountain east Snow Mountain west
Soda
South base:

Redding

.'

Tacoma

Willamette

South Sister

Spencer
Springfield:
Christian Church spire Methodist Church spire
Spur Sqtiaw, cairn
Star

Sterling
Table Rock, cairn

j ^

Position Description

Slretch

Pane. 37
36 35 40 38 35 41 39 36 35 38 42 35
41 41 41 40 38 39 36 35 36
37 37 37 37 35 41 42 41 35 39 39 34 40 39 37 38 35 40 40 37 35 39 35 42 41 38 37 42 34 34 35
37 36 35 40 35
39 39 34 41 36 35 41

Page. 54 52
48
45 56 55 51 47
57 48

Number. 3 7 5 5 5
4,5 6 5
7
5,6 4
7 5

6

56

6

56

6

5

4

5

51

7

47

5

50

6,7

54

3

54

3

54

3

54

3

47

5

56

6

57

7

56

6

46

5

55

5

55

5

44

3.4

6

5

4

4

45

4,5

5

6

4

46

5

56

5

48

5

7

6

4

53

7

7

44

3

43

3

45

4

54

3

52

7

47

5

5

46

5

55

5

55

5

44

4

6

49

6

45

4

6

Pate.
67 64 66 65 65 66
66 65 65 67
66 65 65 66 65 66
64 65
65 66
66 65 65 64 65 66
65
'65 66 66 65 65 66
'67 66 65 67 67 65
65 65
67 64 66 65
65 66 66 65 66

78

THE CALIFORNIA-WASHINGTON ARC OF PRIMARY TRIANGULATION.

Index to positions, descriptigns, sketches, and elevations Continued.

Station