182 TRANSACTIONS OF THE 



it to be sewed, it is turned down as in ordinary hemming, and is 

 beautifully stitched. Hems of various widths are turned, as 50 

 and 51. Other attachments are furnished for special purposes. 



The principles involved in the construction of this machine^ 

 and the details elaborated, are the fruit of the highest inventive 

 genius and mechanical talent. 



It is the invention of Mr. A, B. Wilson, of Cortland county, in 

 this State. His first method of making this double thread lock- 

 stitch, was by a double pointed shuttle which carried the lower 

 thread wound upon a small bobbin within it. The loop of the 

 upper thread upon being thrust through the fabric by the needle, 

 was entered by the shuttle and the line of the lower thread passed 

 through it. Many diflBculties were encountered in sewing by this 

 method. It involved heavy, noisy and cumbersome machinery 

 to drive the reciprocating shuttle; the tension of the lower thread 

 was di£Bicult of adjustment, and varied with the speed of the ma- 

 chine; hence some stitches were more tightly drawn than others^ 

 an objection most evident upon fine material. This fact, coupled 

 with the circumstance of the thread breaking by the sudden jerk 

 of the shuttle before it could unwind from the bobbin, rendered 

 it inadaptable to fine work. Each stitch was completed before 

 another was commenced, hence the slightest lateral movement in 

 the cloth, very likely to occur, threw the next stitch out of an 

 exact line, and gave the stitches a slight zig-zag appearance, 

 ihe lubrication of the shuttle race oiled the shuttle, the thread 

 and the seam. 



Mr. Wilson, therefore conceived the idea of making the stitch 

 by a mechanism totally different in principle, which should obvi- 

 ate all of these objections. In his first invention he had used his 

 superior "rough surface feed," already described. From the 

 " baster plate feed," from which the fabric was suspended upon pins 

 projecting from a plate which was moved forward and a seam 

 formed the length of the plate, and a longer seam by the repeti- 

 tion of this process; the change was to a wheel armed with pins, 

 projecting from its periphery. This gave the advantages of an 

 endless feed, but the pins penetrating the cloth in one place and 

 the needle in another, it could not be well turned to form curved 



