ly succeeding process of "slubbing."

=Bobbin and Fly Frames.=--The series of machines now to be dealt with, are
distinguished more for their complicated mechanism in putting twist into
the attenuated cotton and in winding it upon bobbins in suitable form
for the immediately succeeding process, than for the action of the parts
upon the cotton so as to render it better fitted for the production of
strong, fine yarn.

The manner in which these machines perform a part in the actual
production of a thread or yarn is practically a repetition of the work
of the drawing frame, with the great difference that the strand or thin
rope of cotton leaves each machine of the series in a thinner and longer
condition than when it arrived.

This attenuation of the cotton roving is indeed the chief desideratum
that bobbin and fly frames aim at, although they assist in making the
strand of cotton more uniform by carrying still further to a limited
extent the doubling principle so extensively utilised at the drawing
frames.

The basis of the operations are again the drawing rollers, brought to
such a state of perfection by Richard Arkwright, and here it may be
useful to remind the readers of this story how superior in this respect
of general adaption Arkwright's method of spinning was to that of
Hargreaves'. It will be remembered that the latter named inventor
utilised a travelling carriage, for drawing the cotton finer, while the
former performed the same work by drawing rollers.

Although the travelling carriage principle was at one time somewhat
largely utilised in preparing the rovings for the final process of
spinning, it has long since entirely given way before the superior
merits and adaptability of the drawing roller principle; and it is now
this latter method which is universally employed.

It usually takes three bobbin and fly frames to make up what may be
called a "set," each portion of the cotton roving passing through the
three machines in succession. For low classes of yarn only two of these
machines may be used, while for the finest yarns there are sometimes
four used to make up the "set."

Of course, all the readers of this story must understand that in an
ordinary-sized cotton spinning mill there will be many sets of these
machines, just as there will be a large number of "carding engines" and
"drawing frames," and mules. Bale brakers, openers and scutchers are so
very productive that only a limited number is requ