( *°J ) 
Magnetifin does not alter according to any particular 
power of the didances, but decreafes much fader in 
the greater didances, than it does, in the near 
ones. 
This feems to be confirmed by other Experiments 
I made. Ihefird Experiment was thus* I made a 
Needle ~ of an fnch long, of very fine Steel-wire 
(a Foot length of which weigh’d but a Grain; which 
l lengthen'd by flicking a light piece of Rufli to it, 
fo that I could obferve the Diredion of the Needle 
in all the trials with a Radius of two Inches. Indead 
of a Magnet I ufed a touch’d Needle of Steel- wire, 
which I let on a perpendicular to the Horizontal 
Plane 1 made the Obfervations on, by means of a 
Frame I made to tranfport it from one place to another • 
the North end of the Needle being placed down- 
wards, and made a little fharp, that it might mark 
the Paper it was fet upon in every pofirion, by prefi- 
xing, the top of the Needle gently with the Finger.. 
The Obfervations were made in this manner • after 
having taken notice of the natural diredion of the 
final 1 Compafs Needle, I brought the perpendicular 
Needle as near to it as I conveniently could, fetting 
it in fuch a manner, that a Line from the upright 
Needle to the Center of the Compafs might be per- 
pendicular to the Compafs Needle. Then obferving 
the fame caution (which was convenient to make the 
Center of the Compafs ferve diffidently well to be 
efteem’d its Center of Power) I placed the uprighf 
Needle at feveral greater diflances, every time mark- 
ing the place in the manner already defcribed,and ob~ 
ferving the Variation of the Compafs. By this means 
I got a. Curve pretty regularly and fairly drawn: 
% points on the paper* And by examining 5 this. 
Curve; 
