WEAVING. 
cnlaily Teit in weaving fine or weak cotton 
yarn. Tn weaving, as in every other branch 
of mechanics/ the resistance, or reaction, is 
always nearly as great as the moving power, 
or force, whicli it is necessary to apply. 
From this it follows, that the body of the 
warp must sustain a stress, nearly equal to 
the force, with which the weaver’s foot is 
applied to the treddle. Besides this, every 
individual thread is subjected to all the 
friction, occasioned by the heddles, and 
splits of the reed, between which the 
threads pass, and with which they are gene- 
rally in contact when rising and sinking. 
But the art of spinning has not been as yet, 
and probably never can be, brought to such 
a degree of perfection, as to make every 
thread capable of bearing its proportion 
of this stress equally. It is confirmed, 
both by mathematical demonstration, and 
by practical experience, that when any 
body is to be moved with increased velo. 
city, it is necessary to exert greater power 
to move it ; and as the resistance increases 
in proportion to the power, this sudden ap- 
plication of the pressure of the foot to the 
treddle, must cause a proportional increase 
of the stress upon the warp, and also of the 
friction. Now, as it is impossible to make 
every thread equally strong, and equally 
tight, those whicli are the weakest, or the 
tightest, must bear much more than their 
equal jiroportion of the stress. This causes 
them to be broken very frequently, and, 
even with the greatest attention, more time 
is lost in tying and replacing them, than 
would have been sufficient for weaving a 
very considerable quantity into cloth. But 
when the weaver, from inattention, con- 
tinues the operation, after one or more 
threads are broken, the consequence is still 
worse. AVlien a thread has been broken, it 
no longer retains its parallel situation to the 
rest, but crossing over or between those 
nearest to it, either breaks them also, or 
interrupts the passage of the shuttle ; most 
frequently it does both. 
In every kind of weaving, and espe- 
cially in thin wiry fabrics, much of the 
beauty of the cloth depends upon the woof 
being well stretched. But if the motion of 
the shuttle be too rapid, it is very apt to 
recoil, and thus to slacken the thread, It 
has also a greater tendency either to break 
the woof altogether, or to unwind it from 
the pirn or bobbin, in doubles, which, if 
not picked out, destroy the regularity of 
the fabric. The woof of muslins and thin 
cotton goods, is generally woven into the 
cloth in a wet state. This tends to lay tlie" 
ends of the fibres of the cotton smooth and 
parallel, and its effect is similar to that of 
dressing of the warp. The person who 
winds tlie woof upon the pirn, ought to be 
very careful that it be well bnilt, so as to 
unwind freely. The best shape for those 
used in the fly-shuttle, in cotton weaving, is 
that of a cone; and the thread ought to 
traverse freely, in the form of a spiral or 
screw, during the operation of winding. 
The same wheel, used for winding the 
warp upon bobbins, is also fit for winding 
the weft. It only requires a spindle of a 
different shape, with a screw at one end, 
upon which the pirn is fixed. The wheel 
is so constructed, that the spindles may be 
easily shifted, to adapt it for either purpose. 
That the fabric of the cloth may be uni- 
form in thickness, it is necessary that the 
lay, or batten, should be brought forward 
with the same force every time. In the 
common operation of weaving, this regu- 
larity must be acquired by practice. It is, 
however, of consequence to the weaver, to 
mount, or prepare, his loom in such a man- 
ner, that the range of the lay may be in pro- 
portion to the thickness of his cloth. As the 
lay swings, backward and forward, upon 
centres placed above, its motion is similar to 
that of a pendulum. Now the greater the 
arc, or range, through which the lay passes, 
the greater will be its effect, in driving 
home the weft strongly, and tlie thicker 
will be the fabric of cloth, in so far as that 
depends upon the weft. For this reason, 
in weaving coarse and heavy goods, the 
heddles ought to be hung at a greater dis- 
tance from the point where the weft is 
struck up, than would be proper in light 
work. The point, or rather line, where 
the last wrought shot of weft is struck up, 
is called by weavers the fell. The pivots, 
upon which the lay vibrates, ought, in gene- 
ral, to be exactly at equal distances from a 
line drawn perpendicular to the tell, and 
one drawn perpendicular to the heddles, 
and between these two lines. But as the 
fell is constantly varying in its situation, 
during the operation, it will be proper to 
take the medium. This is the place where 
the fell will be, when a bore (i. e. as much 
as can be woven without drawing fiesli 
yarn) is half wrought np. From thi.?, the 
following conclusion may also be drawn; 
The bores ought always to be short in 
weaving light goods ; for the less that the 
extremes vary fi-oin the medium, the more 
regular will be the are, or swing, of the lay ' 
