u 



( 96 ) 



Jig. 21, Q R S, this I put into a common beer-cup filled with water, 

 and when the Magnet had turned to the North, and was at reft, I 

 took a round piece of iron, about an inch in diameter, and placed 

 it lengthwife clofe to the beer-cup, m hen 1 immediately perceived 

 that the glafs, with the Loadllone in it, inclined fomcwhat to the 

 iron ; whereupon I moved the iron, as gently as 1 could, round 

 about the cup, and the glafs, with the Loadftone in it, immediately 

 followed the motion, but without approaching nearer to the fide^of 

 the cup, and in about a minute's Ipace performed a complete revo- 

 jution. 



After this I placed the iron as clofe as poflible to the cup, in 

 order to difcover whether the attraction between it and the Magnet 

 would be fufficient to move the latter from the middle to the tide of 

 the cup next the iron, but this did not take place though they were 

 left a 'whole night. From thefe things I conclude, that the attrac- 

 tion between the JSIagnet and the iron will fliew itfelf upon the leaft 

 application, fo far as to caufe the circular rotation I have mentioned, 

 but no farther, for very little force is required to efieel this, in com- 

 parifon of that which would be necellary to draw the glals, contain- 

 ing the Loadllone, through the water to the fide of the cup. Ne- 

 verthelefs, I do believe that there might be fome tendency in the 

 Loadtlone towards the iron, and I have no doubt that if this Load- 

 lione had been larger, or of Itronger power, it would have moved 

 to the fide of the cup next tlie iron. 



Once more, I made a much fmaller glafs, of the fame fliape as 

 lafl mentioned, in which I put a fmall piece of Loadltone, not much 

 more than the weight of a grain, and I found that fmall particle of 

 Loadllone to produce the fame efFeel as I had before obferved in the 

 other pieces, and the only ditference in my obferv^ations was, that 

 l\\c larger the Loadlione the quicker were its motions. 



