Mr By water on the Magnetism of Brass-work. SI 
them have hitherto been taken alive. A very large kind of 
rein-deer is also found on those mountains. 
The natives make knives of a white translucent stone, which 
they detach in large sharp-edged flakes, by greasing a portion of 
the rock, and kindling a fire upon it. 
They also dig up an edible unctuous earth, similar, probably, 
to that which is found at the mouth of the Orinooko ; and use 
as a pigment a mineral substance, which they find at the bot- 
tom of a small subterraneous stream. It is in the form of 
round, flattish, ponderous grains, of a shining black colour, 
with a greasy feel, and adheres to the skin only when mixed 
with grease. A large specimen of native silver was also found 
in that neighbourhood in 1796 . 
Near the Great Bear Lake River, there are some coal-mines 
on fire. And there are several fountains of mineral-pitch, one 
in particular, which rises in the channel of the river, at a spot 
which, from that circumstance, is named the Flaming Point. 
Art. XIII.— On the Magnetism of the Brass-work of Surveys 
ing Instruments. By Mr J. Bywater. In a Letter to Dr 
Traill. Communicated by Dr Traill *. 
Dear Sir, 
W NILE residing at Nottingham in the yedr 18 l 0 , some 
magnetical facts came to my knowledge, which may not be un- 
worthy the notice of the Literary and Philosophical Society. 
During the above period, I was applied to by a respectable 
house in the neighbourhood to repair, or more properly correct, 
* A fact similar to that described in the following paper, Was communicated 
to us some time ago by Mr J. Napier, R. N. who observed it at Halifax, Nova 
Scotia, in the summer of 1821. When he was making some observations on the 
Variation of the compass, he was surprised at the sluggish and unsettled motion of 
the needle, and was led to conjecture that some part of the brass-stand belonging 
to the instrument which he used was magnetic. Upon making the trial, he found 
this to be the case, and the degree of magpetism was such as to draw the needle 
from 15 to 20 degrees out of its place, and to retain it in that position when it was 
in contact with the brass. — Ed. 
VOL. VIII. NO. 15 . JANUARY 1823 . W 
