542 TRANSACTIONS OF THE 



one on a safe, in this city, and given notice in the public newspa- 

 pers that a tliousand dollars in that safe may be had by Messrs. 

 Hobbs, Yale, or any body else who can pick it. The common door 

 lock is made for two dollars. Its make is very simple, but its 

 permutations are beyond the reach of figures. 



Mr. Secretary Leonard requested Mr. J. Payne Lowe to explain 

 Singer's new sewing machine. 



Mr. Lowe said that since the premium was awarded by the 

 Institute in 1851 to this machine, the shape of the eccentric piece 

 of metal governing the vertical motion of the needle has been 

 altered, in consequence of which thick leather and fine cambric 

 may be sewn. An additional spring for regulating the upper ten- 

 sion has been added, which prevents the thread from being slack 

 at any time while the machine is in motion. An indentation has 

 been made on the shuttle, the object of which is to prevent great 

 pressure on its surface, and consequently the friction between its 

 bottom part and the plate over which it passes is lessened. There 

 has also been made an alteration in the configuration of the bob- 

 bin. It now turns on the peripheries of its wheels, and will last 

 many times longer than when made according to the old method. 

 All parts of the machine are strong, and consequently durable. 

 The gearing is so arranged that by a continuous motion of the feet 

 the machine will be free from all intermitting impulses. The 

 needle having an up-and-down motion, is not so likely to strike 

 against the throat as it would be if carried by an arm traveling in 

 a curved line: "" The yielding pressure is so arranged as to permit 

 cloth having much inequality of surface to pass readily. The 

 tension of the under thread is regulated by holes on the shuttle. 

 There are five w^ays of threading it. The upper tension is regu- 

 lated by friction over a polished wire, and can be altered at the 

 will of the operator, even while the machine is in motion. The 

 sewing done by this machine is stronger than that done by hand, 

 for the tensions may be so arranged as to give any degree of tight- 

 ness, and to cause the stitches to interlock in either the upper or 

 lower piece of cloth, thus preventing any liability of the threads 

 cutting each other. 



