osely as possible. Careless workers allow the reel
to run on after one or more spinning bobbins are empty, and this
yields what is known as "short tell." It is not uncommon to
introduce a bell wheel with, say, 123 or 124 teeth, instead of the
nominal 120 teeth, to compensate for this defect in reeling.

CHAPTER XII. WINDING: ROLLS AND COPS

The actual spinning and twisting operations being thus completed,
the yarns are ready to be combined either for more elaborate types
of twist, or for the processes of cloth manufacture. In its simplest
definition, a fabric consists of two series of threads interlaced in
such way as to form a more or less solid and compact structure. The
two series of threads which are interlaced receive the technical
terms of warp and weft--in poetical language, warp and woof. The
threads which form the length of the cloth constitute the warp,
while the transverse threads are the weft.

The warp threads have ultimately to be wound or "beamed" on to a
large roller, termed a weaver's beam, while the weft yarn has to be
prepared in suitable shape for the shuttle. These two distinct
conditions necessitate two general types of winding:

(_a_) Spool winding or bobbin winding for the warp yarns.

(_b_) Cop winding or pirn winding for the weft yarns.

For the jute trade, the bulk of the warp yarn is wound from the
spinning bobbin on to large rolls or spools which contain from 7 to
8 lb. of yarn; the weft is wound from the spinning bobbin into cops
which weigh approximately 4 to 8 ounces.

Originally all jute yarns for warp were wound on to flanged bobbins
very similar to, but larger than, those which are at present used
for the linen trade. The advent of the roll-winding machine marked a
great advance in the method of winding warp yarns as compared with
the bobbin winding method; indeed, in the jute trade, the latter are
used only for winding from hank those yarns which have been bleached,
dyed or similarly treated. Fig. 22 illustrates one of the modern
bobbin winding machines for jute made by Messrs. Charles Parker,
Sons & Co., Dundee. The finished product is illustrated by two full
bobbins on the stand and close to a single empty bobbin. There are
also two full bobbins in the winding position, and several hanks of
yarn on the swifts. Each bobbin is driven by means of two discs, and
since the drive is by surface contact between the discs and the
bobbin, an almost constant speed is imparted to