The number of threads brought into operation in this machine is regulated by the pattern to be produced. The threads are of two sorts, warp and bobbin threads. Upward of 9,000 are sometimes used, sixty pieces of lace being made at once, each piece requiring 148 threads (100 warps and 48 bobbin threads). The supply of warp threads is held upon reels, the bobbins carrying their own supply. The warp threads are stretched perpendicularly and about wide enough apart to admit a silver quarter passing edgeways between them. The bobbins are flattened in shape so as to pass conveniently between the warps. Each bobbin can contain about 120 yards of thread. By most ingenious mechanism varying degrees of tension can be imparted to warp and bobbin threads as required. The bobbins, as they pass like pendulums between the warp threads, are made to oscillate, and through this oscillation the threads twist themselves or become twisted with the warp threads, as required by the pattern that is being produced. As the twisting takes place, combs compress the twistings, making them more compact. If the bobbin threads be made tight and the warp threads slack, the latter will be twisted upon the former; but if the warps are brought to a tension and the bobbin threads be slack, then the latter will be twisted on the warps. The combs are so regulated that they come clear away from the threads as soon as they have pressed them together, and fall into position ready to perform their pressing operations again. The contrivances for giving each thread a particular tension and movement at a certain time are connected with an adaptation of the Jacquard system of pierced cards. The lace machine is highly complicated, much of its complexity being due to the mechanism by which the oscillating or lateral movements are produced. Expert workmen prepare the working drawings for the lace machine, and also perform the more important duties in its operation, but a large part of the work is carried on by women and girls. {17} [Illustration: Real Point Applique.]