510 ANNUAL EECORD OF SCIENCE AND INDUSTRY. 



voted to tanning experiments, which proved the invention 

 to be a complete success. Many competent gentlemen did 

 not hesitate in declaring their opinion that the rapidity of 

 the process was little short of marvelous, and that the leath- 

 er produced under it was to all appearance fully equal to 

 that produced by the tedious methods now employed." En- 

 gineer, XL., No. 1033, 263. 



A NEW CEMENT. 



The following recipe is asserted to produce a cement of 

 very superior character for uniting stone and resisting the 

 action of water. It becomes as hard as stone, is unchange- 

 able in the air, and resists the action of acids. It is made 

 by mixing together nineteen pounds of sulphur and forty-two 

 pounds of pulverized stone-ware and glass. This mixture is 

 exposed to gentle heat until the sulphur melts, when the 

 mass is stirred until it has become thoroughly homogeneous, 

 and is then run into moulds and permitted to cool. When 

 required for use it is heated to 248 Fahr., at which temper- 

 ature it melts, and may be employed in the usual manner. 

 At 230 Fahr. it becomes as hard as stone, and preserves its 

 solidity in boiling water. 



ATTACHING LEATHER TO METAL. 



A method of affixing leather to metal, so that it will split 

 before it can be torn off, consists in digesting a quantity 

 of nut-galls, reduced to powder, in eight parts of distilled 

 water for six hours, and filtering it through a cloth ; then 

 dissolving one part by weight of glue in the same quantity 

 of water, and allowing it to remain twenty-four hours. The 

 leather is to be overlaid with the decoction of nut-gall, and 

 the solution of glue applied to the metal, previously rough- 

 ened and heated. The leather is then laid upon it, and dried 

 under pressure. 4 ^, V., 186. 



MARINE GLUE. 



An excellent marine glue, w^hich can be melted at the same 

 heat as common glue, can be applied w^th a brush, sets very 

 quickly, is elastic and perfectly soluble in water, can be 

 made by dissolving two ounces of India rubber in lialf a gal- 

 lon of mineral naphtha. When the rubber is dissolved, add 



