80 



ANNUAL OF SCIENTIFIC DISCOVERY. 



six years of this decade, has been at the rate of over twenty per centum per 

 annum. The operation of this law of increase will soon, it would seem, put 

 an end to all importation of iron, and points even to an export of this great 

 staple at no distant day. The stock and variety of ii-on ores and coal in the 

 United States is such as seems adequate to meet the demands of the world, as 

 fast as the laws of commerce will permit their development. 



ENAMEL WITHOUT LEAD, OX BAR AND SHEET IRON. BY M. 



PLEISCHL. 



The author gives two recipes for the enamel, 



(1) 



Silica, 

 Flint, 

 Kaolin, 

 Pipe clay, 

 Chalk, 



Pulverized porcelain, 

 Boracic acid, 

 Nitre, 

 Gypsum, 



(2) 



from 39 to 50 parts. 



u 

 It 

 u 

 (1 

 u 

 it 

 u 

 u 



Quartz, 



Granite, " 



Borax, " 



Glass, " 



Magnesia, " 



Feldspar, " 

 Effloresced carb. soda," 



Lime, " 



Sulphate of Baryta, " 



Fluor-spar, " 



from 30 to 50 parts. 



20 to 30 

 10 to 20 



6 to 10 

 10 to 15 



5 to 10 

 10 to 20 



5 to 15 



2 to 8 



3 to 10 



u 

 u 



Each of these substances to be powdered separately as fine as possible, 

 mixed carefully, and fused into an enamel ; this is again ground, and applied 

 to the objects, which are then furnaced. The proportions indicated may vary 

 very much with the different kinds of utensils which are to receive it. The 

 coat should be thin, otherwise it will crack in heating or cooling, and the ob- 

 jects coated should be cooled as slowly as possible, so as to prevent the 

 enamel from shrinking irregularly and cracking. Butt. Soc. Encour. de V In- 

 dus, Nat. (Paris.) 



BRONZE OF ALUMINUM. LETTER OF M. CHRISTOFLE TO M. 



DUMAS. 



have applied the aluminum-bronze to two uses for which its qualities 

 of hardness and tenacity appear usefully applicable, and success has an- 

 swered our attempt. The first is the manufacture, in this bronze, of axle- 

 bearings, and rubbing surfaces for machines. We give as examples: 



First, an axle-box which was placed on a polishing-lathe, making 2200 

 turns per minute ; it lasted for nearly eighteen months ; other boxes in the 

 same condition do not last over three months. 



Second, a carriage for a circular saw, making 240 turns per minute, which 

 has lasted for a year without any apparent trace of wear: the carriages in 

 common bronze do not last more than four months. 



The second application is the employment of this bronze in the manufac- 

 ture of guns of all kinds. We made a pistol-barrel, which, after having been 

 tried at Paris, was afterwards at the Exhibition at Dijon. It underwent the 

 tests in presence of the jury, and answered perfectly our expectations. We 

 arc aware that these experiments cannot be conclusive as to its application 

 for artillery; but the comparative experiments which we have made with this 

 metal, bronze, iron, and steel, have shown the immense superiority over 

 those different metals. 



