313 ACCOUNT OF TRIGONOMETRICAI, 



At the commencement tlie old chain ex- 

 ceeded the new one 15.47 divisions of the 

 miciome'-er = (). 00619 ft-^t. Tlieiefne 

 39s X 100.00619 feet will be ihe mea- 

 sure in terms ot" the new chain 



At the conclusion the old chain exceeded 

 the new one 17-9 divi.-^io.js, and had thi re- 

 fore increased 2 43 divisions = OOO07 

 feet. Hence 3yS x ^^ == 0.1930 

 feet, is the correction for the wear, which 

 add - 



The sum of tlie deduc'ions from col. 4th is 

 6.63475 feet, which beino; increased in 

 the ratio of 100 to 100 O0619 wid be 

 6.6351 feet, which subtract - - - 



Hence the apparent horizontal distance will 



be ------ - 



The correction for the e.vpansion and le- 

 duced 10 the standard tempeiature of 69," 

 will be 



(■S3M — 50^ XOOOf-^— fg -''— -^OQ XO 01:37 ^„-Q^ 



0215 feet, which add • - - - 



Hence the corrected measure i; the base 

 for tlie temperature of 62 will be - 



To wli ch add the correction for reducing 

 all the In pothenuses to the level of the 

 south end of the base - - - 



Which being reduced to the level of the 

 .^ea, will be - - . - - 



Feet. 

 39802.4636 



-f 0.1930 



— 6.6351 



39796.0215 



+ 3.1096 

 39799.2211 



+ 0.0893 

 39799.3104 



39793.7 



