122 



On the Sea and Land Rates of Chronometers. 



dence in the country, without finding their rates affected by the re- 

 moval in any sensible degree — certainly not to any thing like the ex- 

 tent which Messrs. A. and D. represent as common. 



After reading the letter of Messrs. A. and D., we took four chro- 

 nometers, and after ascertaining their rates in 'Change Alley, we re- 

 moved them to our private residence, about three miles from thence, 

 and ascertained their rate of going there. We then brought them 

 back to 'Change Alley, and again found their rates. After this, we 

 had them carried around the Royal Exchange in the hand for about 

 half an hour every morning, for several days ; and after this trial we 

 put them in an iron chest for the same period. 



We subjoin the average rates during their various trials, from which 

 it will be seen that no systematic variation took place which could be 

 attributed to the peculiar circumstances under which the chronome- 

 ters were acting. 



Average Rate per Day during each of the Trials. 



No. of Chron. 



At 'Change 

 Alley. 



Private Resi- 

 dence. 



'Change Al- 1 

 ley again. 



! Round Royal 

 Exchange. 



Placed in 

 Iron Chest. 



776 



// in 



-fl 



a in 



+ 1 5 



II HI 



+ 1 3 



H in 



+ 7 



11 in 



+i o 



1978 



= 5 



= 5 3 



= 5 2 



=-5 7 



= 5 2 



745 



= 5 



= 5 1 



= 5 1 



= 5 8 



= 5 6 



925 



= 1 6 



= 1 2 



= 1 4 



= 1 5 



= 1 8 



We may further state on this subject, that, in August, 1833, we 

 sent two of our chronometers, Nos. 1731, and 1751, to the Royal 

 Observatory, Greenwich, on private trial. Their average rates for 

 a short time previous were, 



No. 1731 + 







/// 

 8 



1751 + 03 



per diem. 



After their having been at the Observatory some time, the follow- 

 ing were given to us as the rates they had kept there : 



1731 



At Greenwich . . + 1 2 

 At 'Change Alley + 08 



Difference in Rate + 04 



H III 



1751 





At Greenwich ..+07 

 At 'Change Alley + 03 



Difference in Rate + 04 



It is evident that these chronometers shew no remarkable change 

 of rate, as resulting from their removal from London to Greenwich. 



With respect to the difference between land and ship rates, on 

 which much has been said and written within the last few years, we 



