34 



MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 



parisons were in general made at 11 a. m., local tinie. The expedition chronometers were secured 

 to the floor in the admiral's cabin ; the ship's chronometers were in the navigator's room, with the 

 exception of 425, which was in the admiial's cabin. 



Relative rates of chronometers from daily comparisons. 

 [1340 — Each cbrouometer. Rate given is for twenty-four houra preceding the corresponding date.] 



NEW YORK TO ASPINWALL. 



'Probably an error of 1' in the comparison. 

 ASPINWALL TO CALLAO. 



Note. — Between New York and Aspinwall, the air temperatures changed from 48" to 77° ; between Panama and 

 Callao, from 77° to 63°. 



CALLAO TO CAROLINE ISLAND. 



* Chronometer carried to and from shore. + Checked by a second comparison. 



Note.— The comparisons on March 22 were made in Callao Harbor ; those on April 20 and 21 while the Hartford 

 was lying oflF Caroline Island. 



