PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 525 



Mr. Haskell. — The stitch of Grover & Baker's sewing machine 

 is claimed as an elastic one over all others. It is done by a cir- 

 cular needle and a vertical one. It has a three-fourth revolution. 



Mr. Wood. — I cannot tell how many different patents are em- 

 braced in the Wilson sewing machines, nor do I know how many 

 are embraced in Singer's machine. He (Mr. Wood), presented a 

 book which he said contained a history of patents in general. 



Mr. Haskell produced one of Grover & Baker's sewing machines, 

 and said : The most important improvement is the circular needle 

 in combination with the vertical needle. The vertical needle 

 makes a loop and the circular one passes through it. It has a 

 three-fourth revolution. It produces a loop and leaves a loop in 

 the centre. The next improvement is the feed, and after that 

 the tension. The slack is taken up by a very ingenious motion 

 here in front. The stitch is loosened and tightened alternately 

 as it is required. 



Mr. Orr.— This machine will make about 1500 stitches a min- 

 ute. It makes six stitches to one revolution of the driving wheel. 

 All the attention that is required in the shuttle machines is dis- 

 pensed with in this. It is nearly impossible to do bad work by 

 this machine. If a stitch breaks in any seam made by the Grover 

 & Baker machine it will not rip. 



The Chairman. — How many yards of thread will it take to 

 make a yard of seam? 



Mr. Orr. — About four and a half above, and three and a halt 

 below, making seven and three-quarters altogether. 



Adjourned to Thursday evening next, December 3, 1860, at 

 7^ o'clock, P. M. Subject, "Sewing Machines.' 



American Institute, Polytechnic Association, ) 

 December 13, 1860. > 



Professor Mason in the chair. 



The Chairman, at the opening of the meeting, requested gen- 

 tlemen who wished to propose subjects for future discussion to 

 propose now. He (the Chairman), proposed as a subject, " The 

 best economy of motive power for farm buildings, small manufac- 

 tories and sewing machines." 



Mr. Johnson proposed the subject of " Pottery." 



Mr. Haskell proposed the subject of "drawing from pictures." 



The above subjects were all adopted. 



