feeders. The wheel feed was originally much used for cloth sewing machines,
especially in Singer's system. But in recent years the drop or four motion
feeder has entirely superseded it for such purposes. The wheel feed still
holds its own, however, for sewing leather, especially in the "closing" of
boot uppers, in this country. Singer's original wheel feeder was actuated
by a friction shoe riding upon the flange of the wheel. The friction grip,
however, had certain faults, owing to the tendency of the shoe to slip when
the surfaces became covered with oil.

[Illustration: FIG. 6.]

A later form of Howe's machine used a pair of angular clutches, embracing
the flange of the wheel. In both Singer's and Wheeler & Wilson's latest
styles of machines this arrangement is simplified and improved by the use
of a single angle clutch, which is found to work even when the surfaces are
freely oiled (Fig. 6).

Any motion of the free extremity of the lever upon which the biting clutch
is formed binds the latter upon the flange of the wheel, which then
advances so long as the lever continues to move in that direction. When the
stitch is completed, the clutch is allowed to recede, and is pulled back by
a reacting spring. The bite of the clutch is given by the two opposite
corners.

The feed wheel itself is free to revolve in a forward direction, but is
prevented from rocking backward in Singer's machine by an ingenious little
device, recently introduced. It consists of a small steel roller, situated
within the angle formed by an inclined plane and the flange of the wheel,
and constantly pulled into the angle by a spiral spring. Any backward
tendency of the wheel binds the roller more firmly in the angle and stops