98 PRIMARY TRIANGULATION AND PRIMARY TRAVERSE, [bull. 201. 
Distant mark: North of station 1,400 feet, at base of fence sur- 
rounding Buffalo high school; a limestone post 36 inches long and 
cut 8 inches square at top, set 32 inches in the ground, in the center 
of top of which is cemented a bronze meridian tablet ; true azimuth, 
179° 58' 01.15"; north mark is set 9.69 inches too far west. 
MONTANA. 
TRIANGULATION STATIONS. 
Positions in northwestern Montana, published herewith, result from 
the field work of Messrs. S. S. Gannett, A. H. Thompson, H. L. Bald- 
win, jr., and R. II. Chapman, in the years 1897 to 1901, inclusive. 
They are based upon a geodetic latitude and longitude found by 
taking the mean of the astronomic positions, as determined at Hamil- 
ton and Helena stations, which were connected through a series of 
quadrilaterals. 
Seven positions of stations in the expansion of the Hamilton base, 
published in the nineteenth annual report, are now republished with 
corrected values. 
The Helena astronomic station is a primary astronomic station of 
the United States Coast and Geodetic Survey, situated near the 
United States assay office at Helena, and connected by measurements 
with the court-house spire. 
The observed latitude of the pier is 46° 35' 18.3". 
The observed longitude of the pier is 112° 02' 11.84". 
The corresponding position of the court-house spire is, latitude 
46° 35' 17.5"; longitude 112° 02' 00.94". 
To obtain the geodetic positions adopted, subtract from above 1.57" 
for latitude, and 2.13" for longitude. 
The Helena base (Lewis and Clarke County) was measured twice 
at night with the 300-foot standard steel tape, along the roadbed of 
the Northern Pacific Railroad near Helena, by Mr. R. H. Chapman, 
topographer, in 1897. The resulting length, when reduced to sea level 
and corrected for temperature and inclination, is 6,511.77 meters. 
The Hamilton astronomic station is situated on the eastern side of 
the railroad right of way, 50 feet east of the eastern rail of track, 80 
feet northeast of the station at Hamilton, Ravalli County. The 
quarter corner between sees. 25 and 30, Rs. 20 and 21 W., T. 6 N., is 
distant 339 feet, true bearing N. 39° 13' W. 
Observations for time were made on three nights in July, 1897. 
Telegraphic comparisons of time were made with the Washington 
Observatory, St. Louis, on the same nights. Prof. II. S. Pritchett 
was the observer at the Washington Observatory and Mr. S. S. 
Gannett at the Hamilton station. 
The resulting observed longitude for the Hamilton station is 114° 
09' 09.40" i 0.11". 
