On the Sea and Land Rates of Chronometers. 



125 



on being taken back again to the ship, the rate was found to be 

 6" 5'"; shewing a change in the ship-rate of 3" V". 



Another of them, by a different maker, lost about 9" by its remo- 

 val from the vessel to the shore; and a third, by another maker, still 

 more. The variation in the shore rates is also remarkable, that of 

 the first appearing to have been 8" ; of the second 6"; of the third, 

 7" 2'" ; and of a fourth, 8". And all these errors were noted in 



the short period of seventeen days. 



From the performance of such chronometers, it would surely be 

 unsafe to draw positive inferences as to the effects of any generally 

 operating causes on their rates of going. 



Mr. W. C. Bond, of Boston, in America, a gentleman well quali- 

 fied for the task, has taken much pains to ascertain whether there 

 is any regular and systematic tendency in chronometers to change 

 their rates when put on ship-board ; and, in a paper published in the 

 Transactions of the American Philosophical Society, he has given 

 the result of experiments on a great number of chronometers. 



When he had opportunity, he found the rate before the chronome- 

 ter was sent to sea, and its rate after its return, and he took the mean 

 for the shore rate; and, dividing the change in the error which had 

 occurred while the chronometer was at sea by the number of days, 

 he obtained the sea rate. 



The following extracts are the results from eighty seven chronom- 

 eters made by us, with their different numbers, and whose rates pre- 

 vious to the chronometers being placed on ship-board were accurate- 



ly determine! 



d, an 



d the same a 



fter their return from the voyage : 



■ 



No. of 

 Chron. 



Differ- 

 ence of 

 Rate. 



•g jjjj 1 No. of 



a b«sl Chron. 



° S qj 



Differ- | 



ence of 



Rate. 



O 03 



2 2, '- 



No. of 



Chron. 



Differ- 

 ence of 

 Rate. 



6 &? 



No. of 

 Chron. 



Differ- | 



ence of 



Rate. 



o en 





+0.-1 



zav 







6&>n 







ZQOG 







feed! 



875 



96 



752 



+0.7 



59 



1100 



+0.5 



48 



1146 



-0.4 



47 



928 



0.0 



56 



549 



-0.1 



388 



832 



+0.3 



66 



1179 



0.0 



55 



427 



-0.6 



167 



1035 



+0.9 



■ i a 



1047 



-0.3 



231 



1100 



0.0 



55 



920 



+0.2 



153 



905 



-0.6 



54 



1142 



+0.3 



58 



599 



-08 



56 



966 



-0.3 



46 



871 



-0.4 



200 



1184 



-0.1 



29 



503 



+0.1 



677 



873 



+0.8 



53 



1061 



-1.0 



61 



981 



-0.5 



95 



981 



+0.2 



146 



981 



+0.4 



55 



1090 



+0.1 



109 



1170 



+0.1 



36 



521 



+0.3 



74 



1030 



-0.7 



64 



919 



+0.1 



47 



1006 



-1.0 



37 



947 



-1.0 



254 



920 



+0.7 



157 



981 



+0.3 



| 113 



613 



-0.5 



176 



599 



+0 1 



84 



534 



-0.1. 



63 



125 



-0.2 



Pacif. 



430 



-0.1 



313 



873 



0.0 



95 



871 



+0.2 



186 







Ocen. 



871 



+0.7 



89 



1053 



0.0 



61 



919 



-0.5 



» « a 



• • ■ • 



+0.0 



» * 



866 



-0.4 



101 



1246 



+0.3 



61 



684 



+0.3 



• * * 



727 



+0.4 



28 



832 



+0.5 



114 



966 



-0.6 



112 



889 



+0.1 



• * * 



1030 



-0.7 



57 



1122 



-0.9 



95 



1184 



+0.2 



68 



1056 



-0.4 



52 



&19 



-0.6 



'69 



• • • • 



0.0 



53 



1068 



+0.2 



60 



669 



-0.5 



294 



669 



+0.5 



45 



609 



+0.3 



220 



901 



0.0 



50 



704 



— — i 



+0.3 



62 



• • » • 



-0 7 



187 



966 



-0.3 



120 



1210 



+0.3 



47 



832 



+0.7 



59 



• • • • 



-0.3 



338 



1091 



-06- 



77 



1242 



-0.7 



-47 



1091 



+0.6 



50 



* • • . 



-0.5 



294 



873 



0.0 



27 



635 



+0.3 



102 



1079 



-08 



50 



• • • • 



-1.0 



143 1 



1030 



+0.3 



177 



1100 



-0.2 



57 



891 



■■^ r*^k -^h_ 



-0.3 



161 ; 



811 



+0.5 



136 j 





■ 





1215 



+07 



57 



928 



-0.7 



65 



534 



-0.6 



26 









1030 



-0.3 



202* 



928 



-0.7 



90 



1144 



1 +0.5 



44 





I 









1 



70 tons of iron on board. 



