894 Transactions of the American Institute. 



manufacture of leather, and that the cottton thereby acquires 

 greater strength, and better resists moisture and disintegrating 

 ctlects. The Cosmos does not undertake to explain the chemical 

 reaction wliich produces this important change. We suspect the 

 change cannot be great, since it has escaped the observation of 

 practical tanners. Those who are accustomed to wearing cotton 

 clothes often saturated with tan liquor, as well as similar clothing 

 nntouched by tannin, would not be long in detecting and making 

 known a new virtue in their favorite solution. 



A Spring Motor to Drive Sewing Machines. 



The first novelty exhibited before the Association this evening, 

 was a sewing machine driven by a spring weighing forty-two pounds. 

 It is the invention of Mr. F. Creamer, who claims that his combination 

 is such as to give uniformity to the motions, which, without his appli- 

 ance acts equivalent, would become slower as the spring became 

 weaker ; about six minutes would be required to wind up the spring, 

 which would furnish suflicient power to run a sewing machine one 

 hour. The object of this method of working the sewing machine 

 was to relieve those who cannnot use their feet in driving treadle, 

 and also to give greater freedom to the hands. 



The machine exhibited did not verify the statement of Mr. Creamer 

 regarding its power ; but it was the first constructed, and had 

 defects Vvhich could be easily remedied. 



Mr. G. II. Babcock made the following remarks in relation to 

 plans for driving sewing machines by means of springs : 



Some eight or nine years ago this same subject came up before this 

 Association. I had the honor of calling attention to the fact that 

 some motor wtis required for driving sewing and other small machines 

 for family purposes, and thereupon I was beset by numberless invent- 

 ors, nearly all of whom proposed some form of spring power or 

 clock-work. In order to set this thing at rest, I instituted a series of 

 experiments to determine the amount of spring required to drive a 

 sewing machine for a given time. I first found by trial that to drive 

 a Wheeler & Wilson machine at the rate of 600 stitches per minute 

 required some 550 foot-pounds, or one-sixtieth of a horse-power. 

 This was a light-running fimiily machine, the Wilcox & Gibbs only 

 running lighter. 



I then proceeded to ascertain by experiment how many foot 

 pounds of work could be obtained from one pound of steel. This 



