54 Account of Captain Scoresby’s Magnetical Experiments . 
instrument by the same makers, between the NW. and SE. po® 
sitions, there was a difference, by the first experiment, of 
per day, and by the second experiment, of l°.l. In an eight- 
day chronometer, by Margetts, there was also a sensible effect 
produced by an alteration of position. But the most extraordi- 
nary result was with an eight-day chronometer. When the po- 
sition was kept uniform, the rate of this instrument was very 
fair: but, on shifting it from NE. to SW., it was retarded 
4". 4 daily. On restoring it to its first position, it was again ac- 
celerated even beyond its former rate. The same change was 
repeatedly made ; and in all cases, an alteration of from 4" A to 
9".5 per day occurred ; and, in every instance when the change 
was made from NE. to SW., the rate was retarded ; when the 
contrary way, accelerated ! Between the positions of SE. and 
NW., there was also a difference of rate, but it was not very 
considerable. 
44 As the experiments with the last instrument were by far the 
most decisive, I was desirous of examining the balance, — a wish 
that Mr Davies very readily gratified. It was found to be 
strongly magnetic, acting with great energy on a small needle, 
at the distance of more than an inch. Mr Davies having got rid 
of the greater part of the magnetism of this* balance, restored it 
to its place, when the change of rate, by changing its position, 
though it did not entirely disappear, was got reduced to about 
one-fourth. The balance of another chronometer by the same 
makers, whose rate in all positions was remarkably uniform, was 
also examined, and it was satisfactory to find that it was entirely 
free from magnetism *.*” 
Captain S. we have observed, proposes to get rid of the mag- 
netism in the balances of chronometers, by turning and grind- 
ing them in the plane of the magnetic equator. But he suggests 
another means of rectifying the errors of chronometers, where 
balances are magnetic, by suspending them on an instrument, 
called a Chronometrical Compass , which he has contrived for the 
purpose, and which always keeps them in the same position at 
sea, with respect to the magnetic meridian. This instrument, 
shewn in Plate I. Fig. 2., consists of a slender cross of brass. 
Journal of a Voyage to Greenland , p. 9 - 
