THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FOURTH SERIES.] 



JULY 1854, 



I. On the Vibrations and Tones produced by the Contact of Bodies 

 having different Temperatures, By John Tyndall, Ph.D., 

 F.R.S., Member of the Royal Society of Haarlem, and Pro- 

 fessor of Natural Philosophy in the Royal Institution^, 



IN the year 1805, M. Schwartz, inspector of one of the smelting- 

 works of Saxony, having a quantity of silver in a ladle which 

 had just solidified after melting, and, wishing to hasten its cooling, 

 placed it upon a cold anvil, when to his astonishment sounds, 

 which he compared to those of an organ, proceeded from the 

 mass. The rumour of this discovery excited the curiosity of 

 Professor Gilbert, the editor of Gilbert's Annalen, and in the 

 autumn of the same year he paid a visit to the smelting-works 

 in question. He there learned that the piece of silver from 

 which the sounds proceeded was cup-shaped, had a diameter of 

 3 or 4 inches and a depth of half an inch. Gilbert himself, 

 under the direction of M. Schwartz, repeated the experiment. 

 He heard a distinct tone, although nothing that he could com- 

 pare to the tone of an organ. He also found that the sound was 

 accompanied by the quivering of the mass of metal, and that 

 when the vibrations of the mass ceased, the sound ceased like- 

 wise. The Professor limited himself to the description of the 

 phsenomenon, and made no attempt to expltiin it. 



In the year 1829 Mr. Arthur Trevelyan was engaged in 

 spreading pitch with a hot plastering iron, and observing in one 

 instance that the iron was too hot, he laid it slantingly against a 

 block of lead which happened to be at hand. Shortly afterwards 

 he heard a shrill note, resembling that produced on the chanter 



* From the Philosophical Transactions for 1854, part i. ; having been 

 received by the Royal Society January 15, 1854, and read January 26, 1854, 

 Phil. Mag. S. 4. Vol. 8. No. 48. July 1854. B 



