388 • Patent Substitute for Leather. 



ingots, or into any required form, and when cold, it will have 

 the appearance of an alloy of fine gold and copper. 



The great art in making the alloy consists in working with 

 the lowest temperature ; for if the temperature is too great the 

 zinc will fly off in fumes, and the product will be spelter or 

 hard solder. From this cause it is difficult to make the alloy 

 preserve its character when remelted. The alloy consists of a 

 hundred parts of copper, and of from fifty-two to fifty-five 

 parts of zinc. — Edin. Journ. of Science. 



ACCOUNT OF A PATENT SUBSTITUTE FOR LEATHER. INVENTED 

 BY MR. THOMAS HANCOCK. 



In a former patent, Mr. Hancock proposed to form a sub- 

 stitute for leather, by depositing caoutchouc in a fluid state 

 upon loose fibres of wool, cotton, or flax, felted or matted to- 

 gether. In the present patent, he uses a woven cloth, made 

 of wool, cotton, or flax. When this cloth is stretched upon 

 a flat surface, the composition to be presently described is 

 spread over it. Above the composition, a uniform layer of 

 wadding, made of cotton, flax, wool, silk, or hair, is to be laid, 

 and the whole pressed between a pair of rollers, in order to 

 force the fluid composition among the fibres. It is then to be 

 dried at a temperature not exceeding 80° or 90° of Fahrenheit. 



Mr. Hancock has given us the two following compositions, 

 to be used according to circumstances. 



First composition. — Dissolve two pounds of caoutchouc in 

 one gallon of oil of turpentine and highly rectified coal tar. 

 Add six ounces of black resin, two pounds of strong glue size, 

 and one pound of yellow ochre, whitening, or powdered pu- 

 mice. 



Second composition. — Dissolve l|lb of caoutchouc as before, 

 and having melted and mixed one pound of glue size and 

 resin in a steam bath, add the dissolved caoutchouc to it, 

 stirring while mixing them. The whole must then be strained 

 through a sieve. 



The first of the above compositions must be used when a 

 cheap and stiff' substance is required, and the proportions may 

 be one-third part whitening or glue ; but when a strong and 

 pliant substance is wanted, the second composition, in which 

 the caoutchouc predominates, is to be preferred. 



A substance like leather may be formed by joining together 

 several thicknesses before they are dry. When leather for the 

 soles of shoes is required, Mr. Hancock proposes to use, as 

 tiie groundwork, wool and cotton in equal quantities. For 

 pipes, straps, &c. he proposes chopped hemp and cotton or 



flax; 



