456 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



which serves to cast oif and twist the loop ; a simple form of under four- 

 motion feed, actuated by a crank-pin, serves to propel the fabric, which i3 

 held down upon the serrated feeding-bar by a yielding presser-foot. In 

 the operation of stitching, the needle descends and carries a loop of thread 

 through the fabric, which loop is caught by the front hook of the rotating 

 looper, and receives a half turn or twist, the stitch produced being a twisted 

 chain stitch, which is more secure than the ordinary chain stitch. The cloth 

 is fed forward, and the needle descends again, bringing a second loop with 

 it. This is in turn caught by the front hook, the preceding loop having 

 in the mean time passed into tlie throat of the rear hook, which gradually 

 withdraws from it. and allows it to be finally released only when it is nearly 

 drawn up into the fabric. The rear portion of the looper which effects this 

 operation, is called by the inventor the ' tension-let-off,' inasmuch as it 

 maintains a certain amount of tension on the loop after it has in reality 

 been ' cast oif from the looping hook, the object being to avoid any kink- 

 ing or entanglement of the loop, which sometimes occurs in running at 

 high speeds, if the cast-off loop be left perfectly slack and uncontrolled. 

 The Wilcox <& Gihhs Machine is exceedingly simple in its construction, and is 

 the fastest and least noisy in its action. It is well adapted to family use, 

 and is largely employed in the trimming trade. It is ordinarily run at 

 the rate of 1500 stitches per minute, but can be worked up to 3000 or 4000. 

 " I attribute the former failure of the single-thread chain-stitch machines 

 more to the defective construction of the machines (which were frequently 

 liable to drop stitches) than to the stitch itself, as, when properly made, it 

 will answer for most practical purposes." ***** 



In order to present the readers of these proceedings with a clear idea of 

 this machine, the following cuts and explanations are added: 



Owing to the peculiar construction of the working parts, the machine is 

 rendered perfectly noiseless — a very desirable feature in sewing machines. 

 All the working parts under the cloth plate are covered while in operation 

 by the cap. A, which is hinged at its back end to the frame of the machine 

 by a friction joint. It is shown pulled down in the perspective view, dis- 

 closing the feed mechanism and the revolving looper, B. The machine ia 

 fastened to the table (which is shown projected only) by a thumb screw 

 from the underside, which screws into the frame of the machine; the latter 

 can thus be readily removed to oil and clean it; to perform this operation 

 it is unnecessary to take it apart, as when the cap, A, is pulled open, the 

 works are all exposed. The machine is driven by a round leather belt, 0, 

 which passes over tlie driving wheel of the machine and down through a 

 slot in the table around the balance-wheel. This latter is prevented from 

 turning in an}' direction but the right one (indicated by the arrow), or wear- 

 ing the dress of the operator, by a patented improvement shown in fig. 2, 

 in which A, is the wheel and B, the standard to which is fastened the dress 

 guard, C; a rubber ball, D, fits loosely in a recess and is kept by its gra- 

 vity in contact with the rim of the wheel between which and the recess it 

 wedges when any attempt is made to turn the wheel backward. This pre- 

 vents much trouble and annoyance, especially to beginners. The needle 

 used fig. 5, which together with the manner of adjusting is the subject of a 



