AMERICAN INSTITUTE. 



175 



Fig. 2. 



very firm, cannot be raveled, and will not rip, any more than 



hand sewing. 



In the Wheeler & Wilson machine, this stitch is formed by a 



needle with the eye near the point, and a " rotating hook." A 



loop of the upper thread upon being thrust through the cloth, is 



seized by this rotating hook, carried forward, enlarged, and passed 



around a bobbir- '^arrying the lower thread in the same manner 



as the loop is represented as being carried around the ball in the 



foregoing diagram. 



5, in fig. 2, is the "rotating 



hook " referred to. It is formed 

 by cutting away a portion of the 

 periphery of the circular concave 

 disc upon the end of the arbor. (See 

 fig. 5.) a is the point of the hook. 

 From a is a diagonal groove across 

 the periphery of the hook to the 

 point b, where the edge is be- 

 veled off; 35 is the needle, with 

 the eye near the point, that has been thrust through the fabric, 

 with the thread e, the loop of which has just been entered by the 

 point of the hook a. The lower thread is carried on a double 

 convex metalic bobbin, to lie in the concavity of the hook, and held 

 in its position by a concave ring, (not here represented,) between 

 which and the concave surface of the disc it lies. No axis supports 

 it, so that a loop of thread can pass around it, as around the small 

 ball of thread in the last diagram. 



Fig. 3 represents the hook as 

 having made about two-thirds of 

 a revolution, and the lower 

 thread z, extending from the 

 lower surface of the fabric to the 

 bobbin, in the concavity of the 

 hook containing it. The upper 

 thread e, extends through the 

 fabric, from a previous stitch 

 into the concavity of the hook? 

 behind the bobbin, around the hook at the point b, thence diago- 

 nally along the groove to the needle 35. 



Fig. 3. 



