62 ANNUAL OF SCIENTIFIC DISCOVERY. 



mon salt, (pounded fine) 600 Ibs.; black oxide of manganese, 280 Ibs. 

 1,000 Ibs. These three materials are to be thoroughly intermingled, and 

 reduced to a state of powder, and used in the boiling process to which pig- 

 iron is usually subjected. When the metal is thoroughly melted, and 

 commences to rise, the powder is to be added, in quantities varying from 

 4 Ibs. to 10 Ibs. weight, according to the quality of the metal. If the 

 metal is of a very poor quality, 10 Ibs. weight to the heat of 420 Ibs. of 

 metal, is used ; and as the quality is superior, so less is to be used propor- 

 tionally, up to 4 Ibs., in doing which, the manufacturer must be guided 

 by experience. The powder should be added to, or thrown into the 

 metal, all at once, at the same time stirring briskly about, so that the 

 whole gets thoroughly mixed, and the iron is then ready for use. Cal- 

 cined clay may be used instead of brick-dust. The patentee claims the 

 treating of iron by or with a compound of materials, as above described. 



DURABILITY OF COPPER AND ITS ALLOYS. 



The following extract from Layard's Discoveries in Ancient Nineveh and 

 Babylon, (Appendix iii., page 670, note 3,) evidently shows that copper 

 and its alloys are durable in connection, when so united as to prevent a 

 galvanic current ; but when in mere mechanical connection, such as bolts 

 of iron coming in contact with a ship's sheathing, are destroyed. The 

 specimens collected by Mr. Layard have stood at least three thousand 

 years. 



" This was a very remarkable specimen. It was a small casting, in the 

 shape of the fore-leg of a bull. It formed the foot of a stand, consisting 

 of a ring of iron, resting on three feet of bronze. It was deeply corroded 

 in places, and posteriorly fissured at the upper part. A section was made, 

 which disclosed a central piece of iron, over which the bronze had been 

 cast. At the upper part, where it had been broken off, the iron had rusted, 

 and so produced the crack above-mentioned. The casting was sound, and 

 the contact perfect between the iron and surrounding bronze. It was evi- 

 dent, on inspection, that the bronze had been cast round the iron, and 

 that the iron had not been let into the bronze ; and in this opinion I am 

 confirmed by Mr. Robinson, of Pimlico, who has had considerable expe- 

 rience in bronze casting. 



Composition. 



Topper, 88.37 



Tin, 11.33 



99.70 

 " Some interesting considerations are suggested by this specimen. 



" The iron was employed either to economize the bronze, for the purpose 

 of ornament, or because it was required in the construction. If the for- 

 mer, iron must have been much cheaper than bronze, and * therefore, 

 probably more abundant than has been generally supposed. No satisfac- 

 tory conclusion can be arrived at on this point, from the fact, that bronze 



