96 ANNUAL OF SCIENTIFIC DISCOVERY. 



lodged in the material ; and the fourth, which, with still further re- 

 duced charge, fell without doing injury at the base of the target. It 

 was then turned round, with the Kamptulicon lining towards the gun, 

 at which four shots were also fired. The first two passed through 

 with nearly the same effect, opening the iron to a considerable extent, 

 but the lining closed up immediately, so as scarcely to admit the inser- 

 tion of a small cane at either end, the centre being quite close. The 

 fourth shot, fired with a very reduced charge, rebounded about fifteen 

 yards in a direct line ; thus proving that a shot at a long range would 

 not even enter a vessel so lined. It may also be presumed, from the 

 wonderful resistance of the material, and its repellent power, that noth- 

 ing under a full charge would fire a shot through the two sides. As to 

 its adhesive nature, it need only be said that it occupied a dozen strong 

 men, armed with handspikes and crov/bars, a considerable time to de- 

 tach it from the iron after all this battering. In small portions cut 

 from the different targets may be seen large pieces of iron imbedded, 

 which might cause frightful wounds, and even death, if scattered 

 amongst the crew. 



GLASS COATING FOR IRON ARTICLES. 



AT the late soiree of the President of the Institute of Civil Engi- 

 neers, some specimens of iron manufacture coated with glass were 

 exhibited. In coating plates, roofing-tiles, tubing, kettles, &c., the 

 article is first cleansed in an acid solution, and then covered with a 

 glutinous preparation, over which is laid a coat of glass, ground to a 

 fine powder. The article is then introduced into a furnace of a pecu- 

 liar construction, in which the glass is fused, and, the intermediate 

 glutinous matter being evaporated, the glass fills the external pores of 

 the metal, and becomes firmly united to it. In ornamental dinner- 

 plates, foliage and designs are given in relief, executed by a kind of 

 stencilling; one color being put on, it is transferred to the kiln and 

 fixed ; when cold, another color is added, and so on. London Mining 

 Journal, June 8. 



PROTECTION OF IRON FROM OXIDATION. 



AT the Exposition at Paris, in 1849, there were exhibited* numer- 

 ous articles manufactured of iron, covered with a kind of transparent 

 vitreous coating, completely spread over the surface of the metal, like 

 a varnish, and capable of affording a perfect protection against the ac- 

 tion of the air, or any other oxidizing agent. This invention may be 

 applied to forge or cast iron, no matter what may be the shape of the 

 article. The following is stated to be the process employed in impart- 

 ing to the iron the vitreous surface. The object is thoroughly cleansed 

 by dilute acid, after which it is well washed and dried. It is then 

 brushed over with a tolerably strong solution of gum Arabic. Over 

 the whole of the gummed surface, powdered glass of a peculiar kind 

 is then sifted, care being taken that every part of the surface is well 

 covered. When thus prepared, the work is introduced into a furnace 



