86' Mr. Bennet’s Experiments on a new 
suspended three inches of gold wire of an inch thick, by 
a spider's thread ; about an inch of the same wire was fastened 
to the middle, and hanging perpendicularly from the place to 
which the thread was attached, kept it in an horizontal posi- 
tion whilst undisturbed, and yet suffered it to move up and 
down like a scale beam, by a small degree of motion in the 
air. Under one end of this wire heated substances were intro- 
duced, which caused it to move upwards, seeming to be re- 
pelled by them with as much force, as it was attracted when 
they were applied horizontally. 
Having found that a spider's thread, only two inches and an 
half long, when twisted by above 18,000 revolutions, would 
not cause a sensible deviation of the magnetic needle, owing to 
its very great tenuity, or to its glutinous quality preventing 
its having any tendency to untwist ; and that light substances 
suspended by it, and inclosed in a glass, were capable of being 
turned about by so small a degree of heat as that occasioned by 
a person sitting at the distance of three feet from the instru- 
ment ; or by wires, or other substances, only warmed by hold- 
ing in my hand ; and that when the instrument was placed in 
a cool room, a slight touch with the end of my finger would 
cause the wing of the dragon-fly, or even a bit of straw, to 
point exactly at the side of the glass which had been touched ; 
there could remain no doubt of the freedom with which a mag- 
netic needle would move when thus suspended : yet another 
experiment more directly proves its freedom of motion to be 
Greater than that of former methods. 
O 
EXPERIMENT IX. 
Six rings of horse-hair, made exactly according to Mr. 
