Mr. A. Trevelyan on the Vibration of Heated Metals. S5 



properly smelted, would afford at the first fusion crude steel, 

 which contains a minimum dose of carbon, and to which 

 might be added as much copper as would chemically unite 

 with it, probably from .5 to 7 per cent. But this quantity, 

 I am afraid, would be too small to form an alloy possessed of 

 the strength and power of resistance necessary to made cast- 

 ings for the purposes already mentioned. 



Though 1 have clearly established by numerous experi- 

 ments the practicability of a perfect union of malleable iron 

 with copper, in every reasonable proportion, yet as this alloy 

 can only be made in a close crucible, it is obviously impossible 

 to employ it for castings of a considerable weight or size. 

 I do not, however, despair of overcoming this difficulty, and 

 of gaining the object I have long had in view by a different 

 system of alloy, in which copper must necessarily form an 

 essent ialingredient. — I am, Sir, your very obedient servant, 

 Coleford, Gloucestershire, Dec. 13, 1834. David Mushet. 



XII. Further Notice of the Vibration of Heated Metals ; nsoith 

 the Descriptio7i of a new and convenient Apparatus for ex- 

 perimenting with. By Arthur Trevelyan, Esq,*' 

 CINCE my communication on the above subject, published 

 ^ in your Journal of November 1833, 1 have made numerous 

 experiments ; but the only result I have obtained worthy of 

 notice, is that of vibration accompanied with sound when a 

 heated bar of copper or brass, at a temperature of 208° and 

 212^ Fahrenheit, was placed on a ring of bismuth, having 

 failed in producing it in my previous experiments. With a 

 brass or copper bar placed on a fusible alloy, composed of 

 5 parts of lead + 3 tin +8 bismuth, vibration commenced at 

 a temperature of 203° Fahrenheit. On a ring of fusible alloy 

 containing the same ingredients and in the same quantities as 

 the former, with the addition of one and a half part of mer- 

 cury, no effect was observable. 



The accompanying are figures of a convenient apparatus for 

 experimenting with different metals on a small scale. 



Fig. 1. A gun-metal bar having a groove C, with under-cut 

 edges to receive the wedge ol any metal A, held fast with a 

 pinching-screw B. 



Fig. 2. A gun-metal ring with wedge of any metal inserted in 

 a groove at D. 



Fig. 3. Stand, with two uprights and pinching-screw. The 



* Communicated by the Author, whose former paper will be found in 

 Lond. and Edinb. Phil. Maj^., vol. iii. p. 321. Prof. Forbcs's paper on the 

 same subject will be found in vol. iv. p. 15. 



