as deler mined lij Chronometers at Sea. 25 1 



take place with tlie chronometers on board the Trent, which were 

 four in number 5 and he observes, " It may be worthy of remark, 

 that the chronometers taken out by the Hon.Capt. Phipps showed 

 too great westerly longitude, and consequently gained on these 

 seas. The fact of so many chronometers altering their rates 

 the same wav, is curious ; but I am not aware that any cause can 

 be assigned." 



The effect produced upon one or two of the chronometers ])y 

 their removal to land, was very remarkable ; a chronometer made 

 by Baird was (l)y observations taken on shore near where the 

 ships lay at anchor, by Lieutenants Franklin and Beechey, with 

 false horizon, and eight-inch reflecting circles of Troughton, 

 from August S A.M. to 12 P.M.) losing 3'"4 daily when on 

 board ; but upon its removal on shore to the observatory, its 

 rate per transit, from August 16 to 26, was observed by myself 

 to be lS-"2 losing. Upon again removing it on board, it was 

 found by observation, as before, to be losing 6'"5 daily; from 

 which it appears the chronometer lost no less than about thir- 

 teen or fourteen seconds daily by its removal on shore. 



Another chronometer in the Trent, made by Pennington, had 

 been gaining rapidly on board ; when taken on shore, it acquired 

 immediately a losing rate of 1*"S, nearly the same as it had in 

 London before the vessels sailed. 



A chronometer of my own, by Arnold, was affected likewise 

 nearly as much, losing about 9' daily by its removal on shore. 



In the other chronometers the alteration was less sudden, but 

 was ultimately not less considerable ; and they were several days 

 on shore before they acquired a steady rate, as will appear by 

 the following table of their rates, during the interval of the re- 

 spective dates. 



Tabic of Rates of Chronoweters immediately when landed^ 

 August 9, ISIS. 



1 i 2 



The 



