498 MAJOE-GEXEEAL SABIATl ON THE EESEXTS OE HOrELT OBSEETATIONS 
to communicate with the ship conveying the annual supphes, — Captain ^L^guiee and 
his officers found occupation and interest in the ohsenations which form the subject of 
this Paper, and which, if I mistake not, deser\-e to be ranked amongst the most important 
contributions yet made to our knowledge of the magnetic variations of shoit period. 
The instruments which Captain Maguiee possessed (supphed from Woolwich) were 
two dip circles, one of 9^ inches, the other of 6 inches, each with two needles of 
Baeeow’s construction, and a portable dechnometer, such as is described in Captain 
Kiddell’s useful ‘Manual,’ pp. 15 and 16, ha\ing a peribrated magnet of 3 inches in 
length, carrying a collimator scale in the interior, the divisions of which were read by a 
detached telescope. The observatory is thus described by ]\Ir. Hull, whose zeal and 
assiduity in conducting the observations under Captain INLtguiee’s direction, and accu- 
racy in tabulating them, are spoken of by Captain ALtguiee in terms of the highest 
praise : — “ The observatory was composed of an outer house of ice, 12 feet square and 
7 feet high, within which was another one of seal skin, 7 feet by 6. Two posts, 23 
inches apart, were then sunk, and being firmly frozen into the earth, serr ed as supports 
for the declinometer and reading telescope ; whilst another post was placed in the north- 
western corner for the chronometer, and a pedestal was placed outside the ohserratory 
for the dip circle, which was afterwards removed into a separate house, about 15 feet 
north-west of the observatory. The dip was observed twice a week : we had the misfor- 
tune to break two dip needles through awkward handling, owing to the exti’eme cold. 
The hourly observations with the declinometer commenced on the 5th of Xovember. 
We soon discovered that the aurora was connected with the movements of the magnet; 
the brighter the aurora, the quicker the magnetic changes became ; and fi'om repeated 
observations 1 came to the conclusion, that the appearance of the aurora in the South 
was connected with the motion of the magnet to the east of the magnetic Xorth, and if 
in the North, to the west of the same. In addition to these disturbances, considerable 
irregularities took place in the daytime, generally in the forenoon, and always in cloudy 
and misty weather. During these disturbances it was no uncommon occui-rence for the 
magnet to go out of the field of the telescope, not returnmg again for several minutes, 
and it was generally to the eastward on these occasions. A hea’sy gale from the S.W. 
set in on the 17th December, 1852, and occasioned the loss of five days’ observations. 
It had the effect of raising the water 3 feet above the usual level, and at 3 p.m., on going 
to take the observations, the sea was found washing the wall of the observatory. The 
northern part of the Spit was at this time entirely free from ice, as was also the channel 
as far as we could see, which, owing to the heavy drift, could not he above 100 yards. 
The gale not having moderated, and the water being still on the rise, it was thought 
advisable to remove the instruments, which was fortunately accomplished without injiuy. 
At about 10 P.M. the gale moderated, the sky clearing and shoulng a most beautiful 
aurora, when we found that the ice had gone out of the channel. The next day was clear 
and fine, displaying to us the extraordinary view of open water, until only a few pieces of 
ice in the horizon. From that time not a week passed ivithout a Avell-defined u ater-sky 
