MECHANICS AND USEFUL ARTS. 101 



stitch is that already described, as formed by means of two threads, 

 with a needle and a shuttle. A machine also exists in which two 

 needles are used, the one working horizontally and the other vertical- 

 ly. A machine has been invented by Mr. J. P. Martin, which by an 

 highly ingenious arrangement is self-regulating, and stops whenever 

 the thread breaks, or a loop is missed. The credit of inventing the 

 essential parts of this double thread sewing-machine, is claimed by 

 several parties. It is, however, generally believed, and has been so 

 reported by a Committee of the Franklin Institute, that the employ- 

 ment of a double, or auxiliary thread, as well as the use of the needle 

 with the eye near the point, or at the center, and of the shuttle, are 

 not patentable, but are open to public use. 



The sewing machines which are now in most extensive use, are 

 those known as Singer's of New York, Grover & Baker's of Boston, 

 Wilson's, and Avery's. A new sewing-machine is now manufactured 

 by Ihe Ames Manufacturing Co., at Chicopee, Mass, which combines 

 in one machine the principles of several diiferent patents, which are 

 controlled by the Company. 



Among the machines patented, or first described during the past 

 year, none appear to be possessed of any very new or striking fea- 

 tures, with a single exception. This is a machine recently invented 

 by Tilly Haynes, Esq., of Springfield, Mass., and which for effective- 

 ness, simplicity, and economy of construction, appears to approach 

 nearer to perfection than anv other machine vet brought before the 



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public. Like the other most approved machines, this uses two 

 threads, and is capable of making with the greatest exactness from 

 600 to 800 stitches per minute. We see no reason why this invention 

 should not hereafter become an indispensable appurtenance of every 

 household. 



IMPROVEMENTS IX THE MANUFACTURE OF INDIA RUBBER. 



This is an abstract of the specification of a patent recently granted 

 to Charles Goodyear and Robert Hearing for improvements in the 

 manufacture of India Rubber. " The improvements made are in the 

 moulds which give form to the vulcanized rubber, &c. ; heretofore 

 metal moulds have been used without good results. The invention 

 consists in using or employing sand, pulverized soapstone, plaster, or 

 some similar granular or pulverized substance, and when put together 

 form porous matter, or moulds made of porous substances, to sustain 

 and keep the form of moulded articles composed of caoutchouc or its 

 compounds, and other gums susceptible of vulcanization, during the 

 process of heating or vulcanization. We take articles composed of 

 compounds of caoutchouc or other gums susceptible of vulcanization 

 in the green state. We cause them to be pressed or otherwise formed 

 into the exact shapes which they are required to have, after being 

 vulcanized ; we then cover the surface of the articles with pulverized 

 soapstone, or plaster, or other similar non-adhesive powder. We then 

 place the articles in a box filled with sand, the finer the sand the bet- 



