Bappicker—On the Influence of Magnetism on the Rate of a Chronometer. 35 
The regularity of these differences is very striking, and causes one to regret 
much the absence of east and west observations. The corresponding rates of 
No. 600 in the third column make it probable that this chronometer’s position has 
been equally changed, as differences of rate, though small, also occur with a 
considerable regularity. 
IX. 
[G. Fisner.—S. G. Norrucore. | 
The experiments of Arnold and Dent just detailed above, and especially the 
case of chronometer No. 274, whose rate underwent changes with a change of the 
chronometer’s position, induced George Fisher (No. 19) to see whether observations 
of two of his chronometers might lead to similar results. Their rates were carefully 
determined with the figure XII successively directed towards N., 8., W., and E. 
The cross-arm of the balance, when at rest, was lying in the line XIJ—VI: the mean 
temperatures were obtained for the single intervals of observation. The results 
arrived at with one chronometer only are published in three tables. It appears that 
this chronometer has a tendency to gain in higher and lose in lower temperatures. 
The observed changes of rate, with changes of position, contracted to means, are :— 
I.—Jan. 20, 1836, to March 10, 1836.—Position N., Rate — 0°68 Diff, +. 0-42. 
9 ” 9 9 »P) ” 9 ; 9 S., ” —_ 1 10 
Mar Lost st. spaepral 12, 55 cf Ie ee ace) 
+ 0:35. 
” ” ” ” ” ” ” ” S., ey 0 “69 J ‘4 
Mav 2 re co Sly oy es N., , +0:45 
+ 0°35. 
) ) 9 9) 9) 9 ” 9 S., oP] te 0 ‘10 ia 
I1.—Dee. 3, 1835, to Jan. 11, 1836.—Position W., Rate — 1°18 ) 0.59. 
E NTO ee aoe 
) ? ” oP) ) ”? « 2) 9 “?) ) 
Aprs 1251836, 7,, May 10, ,, A W., 5, —0°30 >) 0-29 
E — 0-08 ANE ES 
” ” ” ” ”) ) 1) 9 ?) ”) 
While Table I. shows a marked difference between the rates in the two posi- 
tions N. and 8., Table IT. causes it to appear very doubtful if the differences observed 
in the W. and E. rates are in any way connected with the change of azimuth or 
with magnetic influence. The average values deduced from the third Table 
are :— 
Position N. minus 8. + 0:27 
ie Wee as. ee O67 
OOS TA ag uations 
* Tn the original misprint :— 
Position W., Rate — 0°:90 
” 10), 9 me thoalfs) Difference + 0°28. 
