Memoir on the Bronze of the Antients. J^t 



The fame thing cannot be faid of the antient brafs. Col- 

 lections of medals contain feveral which have been evidently 

 formed of this alloy, which is known to be factitious, but 

 which Pliny believed to have been a long time before ex- 

 tracted from the bofom of the earth quite formed. 



By the chemical analyfis of the medals of various nations, 

 of a poniard, of a fword, found at Corbie, of nails, &c. all 

 antiques, and of bronze, we have learned that they con- 

 tained tin and fome atoms of zinc, but neither arfenic nor 

 iron were found in them. The proportion of tin varies from 

 four thoufandths to thirteen hundredths, one of the nails con- 

 tained eight hundredths of tin. We know alfo that tin 

 forms a part of the nails ufed for the fheathing of mips, which 

 are driven into the timbers with as much force as is ufed for 

 iron nails. Why did the antients employ bronze alone ? 

 It was notbecaufe the earth prefented that alloy quite formed, 

 fince tin mines do not contain a fenfible quantity of copper, 

 but becaufe they call all their inftruments, and becaufe cop- 

 per alone, though rendered fluid by an extreme degree of 

 heat, remains in the confidence of a pafte. The addition of 

 tin renders it very fluid, and difpofes it to aflume all the de- 

 licacy of the mould. It, therefore, forms a tenth of the 

 metal ufed for cannons, and a fourth of that employed for 

 bells. Befides, bronze is lefs fufceptible of being covered with 

 verdigreafe than pure copper. 



This dangerous effect:, however, cannot be avoided when 

 greafe, acids, and even vegetables, are long kept in bronze. 

 For this reafon the Romans adopted the ufe of tinning, which 

 Pliny fays had been invented in his time by the Gauls ; thefe 

 people they haughtily treated as barbarians, though they had 

 learned from them the art of working iron, and of making 

 ploughs with ears, &c. 



Philo of Byzantium has made us acquainted with another 

 object, which the antients had in view when they alloyed 

 copper with three hundredth parts of tin. It was for the pur- 

 pofe of making elaftic plates, employed in mooting darts and 

 javelins from their warlike machines. He adds, that they 

 hammered them a long time to give them perfect elafticity. 

 This alloy might be employed in our machines, and parti- 

 cularly in carriages for making bronze fprings, which might 

 be fubftitutcd for thofe of fteel, the latter being oft fhort and 

 brittle. Bronze alfo might be fubftituted with advantage for 

 iron in machines, which may be fuddenly deranged by the 

 iron work breaking, fuch as axles for carriages, and hinges for 

 rudders. We have already adopted, for fixing the wheels to 



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