n the cushion is applied to the knife instead of to the plate,
which of course makes the cushion plate, after it has once been set, a
fixture; it also dispenses with the accurate setting, as is now necessary
in the old arrangement. It further does away with the frequent and
expensive covering of the cushion-plate with roller leather and cloth,
thus effecting a considerable saving, not only in cost of material, but
also in labor, inasmuch as the nipper knives can be taken off, recovered,
and replaced in one-sixth the time required to cover the cushion plates
and replace them on the old system. American cotton of 7/8" staple to silk
of 21/2" staple can also be combed by this improved arrangement, an
achievement which has been attempted by many, but hitherto without
arriving at any success. Messrs. Dobson and Barlow have however overcome
the difficulty by their improvements, which combine three important
qualities, viz., simplicity, perfection, and cheapness. Many hundreds of
other makers' machines have been altered to their new arrangements. The
cam for working the nipper has also been altered to give a smoother motion
than usual; one that moves the nipper quietly and without jerks when the
machine runs from 80 to 95 strokes per minute. A very decided improvement
has been made in the construction of the combing cylinder. The combs are
always fixed on a piece called the "half-lap," which, in its turn, is
secured to a barrel called the "comb-stock." Now it is very desirable and
important that these half-laps should be perfectly true and exactly
interchangeable. When one half-lap is taken off for repairs, another
half-lap must be ready to take its place on the cylinder. The original
mode in which the cylinders were made rendered it a matter of mechanical
difficulty--almost an impossibility in the machine shop--to produce them
exactly alike. To avoid this difficulty, Messrs. Dobson and Barlow have
reconstructed the combing cylinder, and the parts being fitted together by
simple turning or boring, accuracy and interchangeability can always be
depended upon. The screws which fasten the cylinder to the shaft are also
cased up with the cylinder tins, thus avoiding any accumulation of fly on
the screw heads.

The motion for working the top detaching, the leather, or the piecing
roller, as it is variously called, has also been improved. The ends of
this roller are always carried on the top of two levers that are
oscillated by a conn