Fig. 9 exhibits the stitching made by this machine upon the edge of the button hole.  Fig. 10 represents the right and left hand loopers and loop spreaders, and for the stitch making.  They rock from right to left with an intermittent motion obtained from a cam.  The left hand looper carries the under thread and interweaves it with the upper, forming the stitch, originally invented, I believe, by Mr. George Fisher, of Nottingham, and reinvented for the button holing machine by D.W.G.  Humphreys, of Massachusetts, U.S.A., in 1862.  The loop spreaders are moved by a roller carried upon the looper frame.  Fig. 11 exhibits the feeding arrangement, both sides of the feed wheel, the driving lever, and the shape of the path given to the carrying clamp by the heart cam cut in the upper surface of the feed wheel.  The picture on the screen represents the upper portions of the machine, exhibiting the conveying clamp, the to and fro dipping motions of the needle bar, and the parts conveying motion to the arrangements beneath the bed plate.  These are shown in Fig. 12, and represent the feed and looper cams, the feeding and looper levers, and the stitch forming mechanism already shown.  A most ingenious device in this machine is the arrangement for automatically lengthening the throw of the feed while stitching around the eye of the button hole.  It is effected by means of a cam, which imparts more or less leverage to the feed arm by the intervention of a “shipper” lever, hinged to the feed lever itself.  The space of time at my disposal obliges me to recommend a personal examination of the machine itself, to fully understand its various motions and its action in working a button hole.

[Illustration:  FIG. 10.]

[Illustration:  FIG. 11.]

[Illustration:  FIG. 12.]

Mention may be made of Singer’s special button hole machine for making the straight holes used in linen work, and in which a shuttle is employed.  Of Wheeler & Wilson’s ingenious button hole machine for the same purpose, I am enabled to show a diagram, in which it will be observed that the feeding arrangements are placed above the bed plate, and are no doubt thereby rendered easily accessible.

Application of Power to Sewing Machines.—­There was a time when a cry arose to the effect that the introduction of mechanical sewing would lead to divers calamities, physical and mental.  The ladies were to become crooked in the spine, and regular operators were to become regular cripples.  It is scarcely necessary to ask, Has this been so?  The operators of to-day are, I think, superior in physical attainments to their sisters of the needle and thread fifty years ago.