LONGITUDE OF WESTERN BOUNDARY LINE. 



149 



In gathering we thus get the following tablet for the chronometer 

 corrections : 



No. 



1S65. 



Chronometer 

 time. 



Ac. 



Probable 

 errors. 



h. 



m. 



sec. 



mln. 



sec. 



see. 



1.... 

 2.... 

 3.... 



4.... 

 5.... 





6 

 14 

 14 



7 

 15 



57 

 ')2 

 50 

 45 

 26 



38 



50 







57 



18 



-17 

 17 

 17 

 17 

 17 



57.14 

 54.58 

 52.68 

 39.06 

 39.04 



±0.51 

 0.38 

 0.46 

 1.50 

 0.31 



Auo-ust 30 



Aue'ust 31 





Sentember 3 





Of these the sets Nos. 1, 2 and 3 enter into the longitude determination, 

 and have been combined in the following manner : First, the mean 

 derived from the morning and afternoon observations of August 30, 

 gives, for 



August 30, 10'> 55"" 14^ chronometer. AC = — 17" 55^86, ± 0».45, 



which is more independent of constant errors, assumed refraction etc., 

 than any single set, either morning or afternoon. Then the daily rate 

 of the chronometer is most conveniently obtained from a combination of 

 sets No. 2 and 3, and comes 



= + 1^90, ±0.=59. 



The mean chronometer time of the telegraph comparisons (which will 



be given immediately hereafter), made on the evening of August 30, is 



20*^ 50°" 0' ; hence the rate for the intervening 20'" 50'" 0^ - 10'" 55'"" 14" 

 =, gh 54m 4Qs^ 



-j-0^78 ±0^24, 



and consequently the correction for the last mentioned instant to sidereal 



time 



= _ 17m 55S.08 ± 0^.51. 



The comparisons just referred to are made by taps at certain beats of 

 the chronometer, the latter being carried to the telegraph office, only a 

 few steps from Mr. Taylor's garden, where the time was taken. A 

 temporary wire had been drawn into the office, so that the circuit went 

 from Hamilton College Observatory to Utica, Buffalo, State Line, Cleve- 

 land, and hence back to the Observatory through the earth. Although 

 the distance along the wires thus was nearly 392 miles, the beats of the 

 pendulum at the Observatory were neat and distinct, as heard at the State 

 Line Station ; and inversely, the signals given at the latter place were 

 very precisely recorded upon the chronograph at Hamilton College. 



