MECHANICS AND USEFUL AKTS. 73 



remain the same forever ; except that it gets louder for the first two or 

 three years that the bell is used, probably from the particles arranging them- 

 selves more completely in a crystalline order under the hammering, as is 

 well known to take place even in wrought iron. 



We may now consider the composition of bell-metal. It is so well known 

 to consist generally of from five to three of copper to one of tin, that all the 

 alloys of that kind arc technically called bell-metal, whatever purpose they 

 may be used for ; just as the softer alloys of eight or ten to one are called 

 gun-metal ; and the harder and more brittle alloy of two to one is called 

 speculum-metal. But you may wish to know whether it has been clearly 

 ascertained that there is no other metal or alloy which would answer better, 

 or equally well and cheaper. The only ones that have been suggested are 

 aluminium, either pure or alloyed with copper ; cast steel ; the iron and tin 

 alloy, called union-metal ; and perhaps we may add glass. The first is, of 

 course, out of the question at present, as it is about fifty times as dear as 

 copper, even reckoning by bulk, and much more by weight. I have not 

 heard any large steel bells myself, but I have met with scarcely anybody 

 who has, and does not condemn them as harsh and disagreeable, and having 

 in fact nothing to recommend them except their cheapness. Much the same 

 may be said of the iron and tin alloy, called union-metal. I have seen also 

 some cheap bells, evidently composed chiefly of iron, but I do not know 

 what else, and they are much worse than the union-metal bells. It is 

 hardly necessary to say much of glass, because its brittleness is enough to 

 disqualify it for use in bells : but besides that, the sound is very weak, com- 

 pared with a bell-metal bell of the same size, or even the same weight, and 

 of course much smaller. There is another metal, which you will probably 

 expect me to notice as a desirable ingredient in bells, that is silver. All 

 that I have to say of it is, that it is a purely poetical and not a chemical in- 

 gredient of any known bell-metal ; and that there is no foundation whatever 

 for the vulgar notion that it was used in old bells, nor the least reason to 

 believe that it would do any good. I happened to hear of an instance 

 where it had been tried by a gentleman who had put his own silver into the 

 pot at the bell-foundry, some years ago. I wrote to him to inquire about it, 

 and he could not say that he remembered any particular effect. This seemed 

 to me quite enough to settle that question. You may easily see for your- 

 selves that a silver cup makes a rather worse bell than a cast-iron saucepan. 

 Dr. Percy, who had taken great interest in this subject, has cast several 

 other small bells, by way of trying the effect of different alloys, besides the 

 iron and tin just now mentioned. Here is one of iron ninety-five, and an- 

 timony five. The effect is not very different from that of iron and tin of the 

 same proportions, and clearly not so good as copper and tin ; and I should 

 mention that antimony is generally considered to produce an analogous 

 effect to tin in alloys, but always to the detriment of the metal in point of 

 tenacity and strength. Again, here is a bell of a very singular composition, 

 copper 88 - 65, and phosphorus 1T35. It makes a very hard compound, and 

 capable of a fine polish, but more brittle than bell-metal, and inferior in 

 sound even to the iron alloys. Copper 90'14, and aluminum 9'86, which 



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