( 9* ) 



But the motion produced in the glafles by thefe pieces of Load- 

 ilone was fo feeble, that I judged if a power not equal to the 

 thoufandth part of a grain, had been oppofed to the fmall glalles, 

 it ^^'ould have given them a different direAion ; for thefe particles 

 of Loadftone had vciy little virtue in them, if compared with what 

 I have heard boalled refpecting other Loadltones. 

 ~ INloreover, I made another glai's veffel, to contain a piece of 

 Loadllone ; the fhape of which vell'el is fliewn at Jig. 22, A B C D 

 E F G H I K, and in the cavity of tliis, at A B C 1 K, a fragment 

 of Loadftone was placed, as marked at L. The lengtli of this 

 glafs, from C to D, was almoft nine inches ; the cavity in which 

 part was about the thickneis of an hortc hair. I purpolcd to make 

 the part, D E M, with a cavity of jull fuch a tize, that by means 

 thereof a fmall part only of the glafs might rife above the furface 

 of the water : and, after three feveral trials, I made the glafs fo 

 to my with, that the upper part of the cavity, D E F, barely ap- 

 peared above the furface. The reafon why I made this glafs of 

 fuch a length was, partly that I might fee whether the particle of 

 Magnet, when fo deep under the water, would yet have power to 

 turn its North pole towards the North, and lb to caule the glafs 

 vellel to change its polition ; and partly to obfei-ve w hether, when 

 funk fo deep, it would be at all affected by iron brought clofe to 

 the furface of the water. This being done, I turned round the 

 part, F G, feveral times ; fometimes with a quicker and fometimes 

 with a flower motion ; and I always found that it would not remain 

 at reft until its extremity, G, pointed towards the Eaft. 



I could not make this experiment in a beer-cup, by reafon of 

 the length of the glafs ; therefore I took a wooden veffel of that 

 fort which are ufed in this country to meafure charges of powder 

 for guns, and called by us, cardocs-dooj'en, which may be rendered 

 in Englifli, cartridge-boxes. 



After this I made another glafs, the thinneft part of which, fimi- 

 Jar to what is pidured in fig. 22, at C D, was thirteen inches long: 



