Hollow Spheres of Metal by Heat. 9'^ 



J. 4 inches diameter ; 2425 grains weight. 



K. G reduced to 493 grains weight. 



L. J ,3 „ 991 „ „ 



M. B „ „ 343 „ 



N. C reduced to 342 grains weighty and a bar of German 



silver weighing 228A grains replaced within it; total 



weight 570i grains. 

 0. I deduced to 372| grains weight. 

 P. L „ „ 561 „ „ 



Eocpei'iments. 



No. 1. The copper ring silvered all over, and rather thickly 

 upon its edges ; raised to a moderate red heat : the ball A placed 

 upon it did not vibrate or show any signs of motion. The ball 

 D immediately placed upon it, began at once to vibrate through 

 a space of one-sixth the circumference of the ring, and continued 

 to do so for 25 minutes, until the ring was quite cool. 



No. 2. The ring as in experiment No. 1, but rather less 

 hot ; the ball A showed no motion ; and the ball E vibrated less 

 than D^in experiment No. 1. 



No. 3. The ring thickly coated with \^ ounce of silver upon 

 its edges by electro-deposition, and raised to a full red heat, the 

 silver became very much blistered, but was partly remedied 

 by rubbing with a burnisher. Ball B exhibited a feeble tendency 

 to vibi*ate. Ball C vibrated backwards and forwards about one- 

 fifth the circumference of the ring. Ball F vibrated complete 

 revolutions within about one-eighth of an inch during several 

 minutes. Ball G vibrated through one-sixth the circumference 

 of the ring. Ball H vibrated about one-fourth of a complete 

 revolution. Ball J exhibited no signs of motion. N.B. The 

 ring was only once heated for this experiment. 



No. 4. The coating of silver was removed from the edge of 

 the outer rail, and the ring was heated to a full red heat. Ball 

 F vibrated through one-fourth of a revolution. Ball I exhibited 

 decided motion, but less than ball F. Ball K made 7 complete 

 revolutions in 1 minute in a right-handed direction, i. e. in the 

 same direction as the hands of a watch. Ball L vibrated through 

 one-fourth of a revolution. N.B. The ring was only once 

 heated for this experiment. 



No. 5. The ring as in No. 4; heated to bright redness. Ball 

 M made about G revolutions in half a minute, in a left-handed 

 direction. Ball N made about 4 revolutions in half a minute 

 in a similar direction. Ball K made about 3 revolutions in half 

 a minute in the same direction. N.B. The ring was only heated 

 once for this experiment. 



• No. G. The ring as in No. 5, and heated uniformly to bright 

 H2 



