28 



MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



ing table contains the mean rates of each chronometer New York to Aspinwall, the mean relative 

 rates from these figures, then the relative rates at Aspinwall, obtained as above. The diflerences 

 are large, and in the absence of any evidence as to the superiority of any one chronometer it is 

 assumed that the differences should be distributed equally between 1340 and the chronometer 

 compared with it in each case. The corrected rates of 1340 are therefore obtained as given in the 

 sixth column, and the mean taken, rejecting the comiiarison with 202, as it was the hack chronom- 

 eter and ran irregularly. The rates in the last column ai-e the values adopted for the rates at 

 Aspinwall. 



Table II. — Rates of each chronometer at Aspinwall. 



The chronometer comparisons between Aspinwall and Callao showed departures from the 

 above values. These comparisons were treated in a manner similar to that above given for 

 determining a correction to the rate of 1340, and hence to that of each chronometer. The following- 

 table gives the results : 



Table III. — Mean rates adopted, Aspinwall to Callao. 



By means of the rates given in the last column of Table III, the correction of each chronometer 

 was obtained for the time of the first comparison of chronometers in Callao Harbor after their 

 removal to the Hartford. The resulting corrections of 1340 from each chronometer (rejecting 202) 



are: 



Corr. to 1340, March 22.140. 



m. s. 



By rate -7 11.7 



From 1580 11.3 



2786 11.5 



1.53G 10.8 



Mean -7 11.3 



