12 SPIRIT LEVELING IN NEW YORK, 1896 TO 1905. 
ALBANY, ALLEGANY, BROOME, CATTARAUGUS, CHEMUNG, 
OTSEGO, SCHENECTADY, SCHOHARIE, STEUBEN, AND TIOGA 
COUNTIES. 
AMSTERDAM, APALACHIN, BATH, BERNE, BELMONT, BINOHAMTON, CAMERON, (!ANASERA(U, 
CHERRY CREEK, COHOES, COOI'ERSTOWN, CORNING, DELHI, DUNKIRK, ELMIRA, 
tiOWANDA, HORNELLSYILLE, NINEVEH, OLEAN, ONEONTA, OWEOO, REDHOUSE, RI( II- 
MONDVILLE, SALAMANCA, SCHENECTADY, SCHOHARIE, SHONGO, SIDNEY, AND WAVERLY 
QUADRANGLES. 
'The elevations in the following list are the result of a line of precise levels run between 
Dunkirk and Binghamton over the line of the Erie Railroad and between Binghamton and 
Cohoes over the line of the Delaware and Hudson Canal Company's Railway. Between 
Dunkirk and Elmira the line carried eastward was based on the top of the water table of 
Nelson Block, Dunkirk, and all bench marks in this portion of the line are stamped with 
the legend " D 1898 " in addition to their figures of elevation, thus referring them to the Dun- 
kirk datum. The section between Cohoes and Elmira was run westward based on the old 
Gristmill bench mark near Albany, and are stamped "A 1898" in addition to the figures of 
elevation, thus referring them to the Albany datum. 
The double-rodded, simultaneous, direct and reverse method was used, with a Bud' & 
Berger precise level, and the rods used were targeted on one side and self-reading on the 
other. The result of the targeted line in each section was used alone as the adopted line, 
that face having been tested, the line employing the self-reading faces being used as a check. 
The closure at Elmira between the two lines was 0.645 foot, but there is a greater difference 
between the datum of figures stamped on the bench marks on account of an error of 
1 foot in the elevation started with in the east section, which was not detected until work 
was finished. 
The elevations used for the aforesaid bench marks prior to 1899 were derived by sub- 
tracting 1.085 from t he elevations then used by the army engineers, and the aforesaid closure 
represents the error between the Geological Survey line and the old data furnished by the 
army engineers, which are now superseded by the recent precise leveling. 
The differences of elevation between the various bench marks as shown by the duplicate 
rodded lines was very small, the final divergence being — 0.196 foot for I he direct line going 
eastward and — 0.224 foot for the direct line going westward, making a, total closure of the 
target upon the self-reading rod lines -\- 0.028 foot at Schenectady. This divergence is far 
within the limit set for precise leveling. 
This line is composed of six elementary lines used in the 1903 adjustment of the precise- 
level net by the United States Coast and Geodetic Survey, which adjustment supersedes its 
former adjustment of 1900, in which this line formed but one link, and the previous local 
adjustment by the Geological Survey deriving elevations for these bench marks published 
in the Appendix to the Twentieth Annual Report of the Geological Survey, Part I. From 
Dunkirk eastward the six main junctions with other level lines are at Salamanca, Hornells- 
ville, Elmira, Binghamton, Bainbridge, and Rexford Feeder Bridge (Schenectady). 
The corrected elevation for the Nelson Block bench mark is now accepted as 588.866 feet 
above mean sea level, and the unadjusted line raised to accord with the latter has now been 
corrected at the other junctions aforesaid, respectively, by the following amounts: +0.250, 
+ 0.286, + 0.236, + 0.232, + 0.161 and —0.005; the corresponding distances from Dunk irk 
being 44.1, 129.3, 187.7, 246.3, 283.6, and 381.8 miles. The algebraic difference between 
consecutive figures of the first or second lines is the amount distributed or the distance 
between those points, respectively. 
The leveling was done by Mr. E. L. McNair (now topographer) in the field season of 1898. 
DUNKIRK, ALONG THE ERIE RAILROAD, TO ELMIRA. 
DUNKIRK QUADRANGLE. 
Foot. 
Dunkirk, St. Mary's Home and School, Washington avenue, between Third and Fourth 
streets, in water table 20 feet from northeast corner; aluminum tablet stamped "598 DUN- 
KIRK 1899 " 598. 936 
Dunkirk, Nelson Block, extreme northwest corner of, on top of water table; chiseled cross.. . 588. 86G 
