126 On the Land and Sea Rates of Chronometers. 



Summary. 



No. of No. of Days 

 Chron. at Sea. 



Number of trials, . • 87 



Number wherein the average shore rate differed from 



the ship-board rate — and the difference, 

 Number wherein the difference was one second, 



do. " ", do. 



do. " " do. 



do. " " do. 



do. i " * do. 



do. " " do. 



do. " " do. 



do. " " do. 



do. " " do. 



do. " " do. 



C( 



a 



ii 



ii 



ti 



a 



a 



a 



a 



)ne second, 



• 



4 



37 to 254 



- 9 -of 



1 U1 



a second, 



2 



— to 95 



8 



To 



do. 



• 



3 



50 to 56 



7 



1 



do. 



• 



11 



47 to 157 



1 



do. 



• 



7 



27 to 169 



5 

 1 



do. 



• 



10 



44 to 294 



4 

 I 



do. 



• 



7 



28 to 200 



3 

 1 



do. 



• 



17 



46 to 338 



2 



1 



do. 



• 



8 



57 to 286 



1 



To 



do. 



• 



9 



25 to 677 



i 



Number wherein there was no difference whatever, 9 27 to 95 



It is evident from these experiments, that there is no general ten- 

 dency in these chronometers either to gain or lose at sea, on their 

 land rates ; as it appears from the above, that, out of eighty seven 

 trials, thirty nine gained on their rates, and thirty nine lost on their 

 rates : the remaining nine made no variation whatever. 



Mr. Barlow, of the Royal Military Academy at Woolwich, whose 

 attainments in science, skill as an experimenter, and discoveries on 

 the laws of magnetism in particular, are known to all scientific men, 

 took up the subject on the appearance of the Rev. Mr. Fisher's pa- 

 per, and published the result of his inquiries in the Transactions of 

 the Royal Society. He found, indeed, that chronometers were in- 

 fluenced by their near proximity to masses of iron ; but instead of 

 the rates of those which he tried being accelerated, five of the six 

 which he used were retarded, and the acceleration of the sixth was 

 doubtful. 



We may be excused for stating, that the one least affected was 

 made by us, and it was constructed on the same principle as the four 

 mentioned above by Captain Sabine, and whose performance, under 

 such extraordinary circumstances, was to us a subject of gratifying 

 remark. 



That a material effect on the going of a chronometer would be 

 produced by applying a powerful magnet to it, we have no doubt, as 

 the magnet would then operate as a disturbing force with all the ad- 



