126 On the Land and Sea Rates of Chronometers. | 
Summary. 
J No. of - No. of Days 
Chron. at Sea. 
Nite ference) ents Mtoe devon ined yah any 
Number wherein the average shore rate differed from 
' the ship-board rate—and the difference, .  . 
Number wherein the difference was one second, . 4 387 to 254 
do. 3: Rs do. « 8 ofasecond, 2 —to 95 
do. Ke RS do. npaned do. » 3 50to 56 
do. sg of do. eae do. . 11 47 to 157 
do. ce i do. oii do. 27 to: wee 
do. ee iM do. ee do. . 10 44 to 294 
do. ee ey do. Gil dol) i) w2eitov2ue 
do. Cece don ne ey don (ea Ontos aS 
do. connec doe ee ae andor. 8.) Suite 
do. rh it do. “ods do. )...).9.,.25, to. Oaw 
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 prowimity 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- 
