64 Progress of Invention. 



of the carbonate of ammonia in urine, which has spontaneously 

 decomposed, immersing the zinc in that fluid instead of in the 

 sulphate of the peroxide of iron. According to his experiments, as 

 detailed to the Academy of Sciences, the resulting battery is not 

 only cheap, but effective. It is probable that zincate of ammonia 

 and carbonate of zinc are formed during the action which takes 

 place. 



Photography under. Water. — No place is now safe from the 

 incursion of photographers. • Who would suppose that they could 

 carry on their operations under water ? Yet such is now the case, 

 as M. Bazin has proved. His photographic studio consists of a 

 strong sheet-iron chest, perfectly water-tight, with water-tight 

 windows, that are in the form of lenses. The electric light is used, 

 and renders distinctly visible any objects lying at the bottom of the 

 sea, so that they may be photographed, and thus their nature and 

 position be accurately marked. M. Bazin has remained at depths 

 of nearly three hundred feet for about ten minutes. This applica- 

 tion of photography promises to facilitate the recovery of lost 

 objects, and the raising of sunken ships, etc. 



A New Petroleum Lamp. — A lamp has just been contrived by 

 M. Leplay, of Paris, that promises to be a very interesting addition 

 to man's appliances for purposes of domestic illumination. The 

 lamp consists essentially of a hollow ball of brass, mounted upon a 

 stem and stand. The ball is closed at the top by a closely-fitting 

 plug. When this plug is removed, the opening is seen to lead into 

 an interior cylinder, or space separated from the rest of the interior 

 cavity by a roll of metallic gauze. Between the gauze cylinder, 

 and the external wall, the lamp interior is packed with sponge. 

 When the lamp is to be charged, a quantity of a light and cheap 

 form of Benzule, distilled for the purpose, is poured into the space, 

 and the superabundance, over and above what is sufficient to satu- 

 rate the sponge, is poured back again from the lamp, and the plug 

 is closed. The lamp is then ready for use. The interior space of 

 the lamp is immediately filled with the elastic vapour of the Benzule, 

 which pours out as a stream of inflammable gas when the plug is 

 removed. When this stream is lit it continues to burn with a bright 

 clear flame, until the sponge is exhausted b} r the process of spontaneous 

 evaporation. About two-thirds of an ounce suffices to charge the 

 sponge, and this charge enables the lamp to burn for about eight hours. 

 This is the extraordinary part of the affair. The light of the flame 

 is equal to something like that of two composite candles. The 

 lamp may be turned over, and rolled about the floor upon its side, 

 without in any way interfering with its burning, otherwise than by 

 causing the flame to keep itself turned up at right angles to the 

 vertical axis of the lamp. There is, of course, nothing to spill.. If 

 the lamp is turned upside down and jogged, while burning, it 

 becomes apparent that the Benzule gas is heavy. The flame then 

 drops from the lamp in successive sparkles. A considerable number 

 of the lamps are to be immediately sent over to England for public 

 sale. 



