CXV1 
APPENDIX. 
The hours have been noticed at which the preceding observations were 
made, because the results obtained at different times of the day agree suffi- 
ciently with each other, to justify an inference, that no very considerable 
diurnal change took place in the direction of the needle. 
A Variation Needle, made by Mr. Dollond, being the property of Henry 
Browne, Esq. F. R. S., who was kind enough to spare it for the occasion, had 
been embarked with the other instruments ; it had been used in England to 
observe the amount of the hourly changes in the variation, which it did with 
much accuracy; but the needle being nearly a foot in length, and being 
suspended in the customary manner, by an agate cup on a metal point, the 
friction on the point was too great to be overcome by the directive power of 
magnetism, when the dip had increased to 88° or 89°; the instrument was 
therefore quite useless at Winter Harbour. 
It may indeed be justly regarded with surprise, that under so great a 
diminution of the magnetic influence, any compass should have still been found 
to traverse ; and it is therefore deserving of especial notice, that even in such 
extreme circumstances, Captain Kater’s excellent compasses, when used on 
shore, and with patience and attention to frequent tapping, indicated the 
meridian with very tolerable precision ; the greatest difference of any two in 
ten observations not exceeding between three and four degrees. 
The inference which has been drawn above, that the diurnal changes were not 
very considerable, may be strengthened by a remark, that had they been so they 
could scarcely have failed to have been observed by the instrument for ascer- 
taining the intensity of the magnetic force, which was frequently left for days 
together in the observatory, and carefully watched. The needle of this instru- 
ment was suspended by a silk line within a graduated ring ; and, though not 
equal to the measurement of small changes, would certainly have shewn them 
had they exceeded a degree in amount. 
