Magnetical Experiments , tjrc. 5S 
that an irregularity observed in the rate of some time-pieces, was 
owing to the magnetic state of their balances. He was directed 
to the inquiry by a watch of excellent workmanship that he had 
in his possession, which performed the most irregularly of any 
watch he had ever seen. It occurred to him that the cause 
might be magnetism ; and, on examining the balance, he found 
it so strongly magnetic, that, when suspended horizontally with- 
out the spring, it directed itself like a compass-needle in a certain 
position, which it invariably returned to when it was disturbed. 
The pendulum spring being put on, and the balance replaced m 
the watch, Mr Varley laid the watch with the dial upward, and 
the north pole of the balance, as determined by the previous ex- 
periment, towards the north in this situation it gained 5' 35" 
in twenty-four hours. He then directed the north-pole of the ba- 
lance towards the south, every thing else being as before, and it 
now lost 6' 48" in twenty-four hours. Mr Varley afterwards took 
away the steel-balance, and substituted one made of gold ; then 
having brought the watch to time, he carefully observed its 
rate, and found it as uniform as any watch of like construction. 
He subsequently examined many dozens of balances, out of 
which he could not select one that had not polarity.*” 
The instance observed by Mr Varley was, no doubt, an ex- 
treme one ; but analogous effects are not uncommon. Captain 
Scoresby made a number of experiments on the rates of chrono- 
meters in different positions, and found, that in twelve or four- 
teen chronometers, a sensible alteration of rate took place in 
about one-half of them, without any alteration of position. 
44 In a pocket chronometer,” says he, 44 by Allen and Caithness, 
the rate was very uniform in two positions (namely, with 'the 12 
o’clock mark towards the NE. and SW.) ; but on shifting it from 
NE. to SE., a change of l /7 .5 took place in its rate. In 
another chronometer by Hatton, there appeared to be a dif- 
ference of rate of about a second in two opposite positions. 
In a one-day chronometer by Litherland and Davies, there was 
scarcely any perceptible variation in three positions, namely N., 
S. and E. ; but, on the 1 2 o’clock mark being directed towards 
the W. ? a change of one second per day occurred. In another 
Edinburgh Transactions . vol. ix, p. 353. 
