28 
PRIMARY TRIANGULATION AND PRIMARY TRAVERSE, [bull. 216. 
DERRY, ROCKINGHAM COUNTY. 
In town of Londonderry, 3 miles a little north of west from village 
of Berry, 270 feet south of schoolhouse No. 8 on northwest of slope of 
hill. The summit, which is about 400 feet southeast of station, is 
covered by dense growth of pine. 
Station mark: A bronze triangulation tablet cemented in largo 
granite bowlder. 
[Latitude 42 54 04.85 
'. Longitude 
71 22' 39.72".] 
To station— 
Azimuth. 
Back azimuth. 
Log. distance. 
Hudson . . _ - . 
5 35 23. 7 
70 31 33.7 
117 55 31.1 
155 40 27. 1 
185 34 45. 9 
250 25 30.2 
297 46 53. 6 
335 37 56. 2 
Meters. 
4.11220 
Turkey 
Unkonoonuc 
4. 10925 
4. 28958 
Manchester . 
4. 08553 
NEW YORK. 
TRIANGULATION STATIONS. 
Mr. A. H. Thompson, geographer, extended triangulation westward 
from the vicinity of Olean nearly to the western border of the State, 
controlling 4 quadrangles in Cattaraugus and Chautauqua counties 
and he also located by triangulation 5 stations for the control of i } 
quadrangles in Wyoming and Livingston counties. 
Mr. Oscar Jones, topographer, controlled b} 7 triangulation the Car- 
thage quadrangle in Lewis County by locating 5 stations from the line 
Elmer-Rock. 
Mr. McNair controlled 2 fifteen-minute quadrangles in Genesee 
County by locating 5 stations from Conesus, Perry, and Scottsville. 
Positions are given on the II. S. standard datum. 
DAVIS, ALLEGANY COUNTY. 
Located in the northern part of Centerville Township about 2 miles 
north of Centerville village on land owned by Milton Davis. 
Station mark: A bronze triangulation tablet cemented in solid rock 
under center of signal. 
[Latitude 42 31' 02.22 
". Longitude 
78° 14' 36.23".] 
To station- 
Azimuth. 
Back azimuth. 
Log. distance 
Carpenter 
176 ^0 39. 24 
227 29 55.55 
258 10 54.79 
356 40 09.55 
47 38 39.19 
78 25 47. 18 
Meters. 
4 2363363 
Felch 
Nunda . . » 
4. 3784343 
4 4878673 
