WEAVING. 
jicrsoii is placed behind. The former opens 
every heddle in succession, and it is the 
business of the latter to select every thread 
in its order, and deliver it to be drawn 
through the open heddle. The succession 
in which the threads are to be delivered is 
easily ascertained by the rods, as every 
thread crosses that next to it. The warp, 
after passing through the heddles, is next 
drawn through the reed by an instrument 
called a sley or reed-hook, two or more 
threads being taken through every interval. 
These operations being finished, the 
cords or mounting which move the heddles 
are applied ; the reed is placed in the lay, 
or batten, and the warp is divided into small 
portions, which arc tied to a shaft con- 
nected by cords to the cloth-beam. 
When the weaver has finished these two 
operations of beaming and drawing, he pro- 
ceeds to dress his warp. And here it should 
be remarked, that the operation of dressing 
applies principally to cotton. The same 
practice, when used upon silk, has a very 
destructive tendency ; which is that of in- 
juring the colours of the silk; and when used, 
as it sometimes very improperly is, by 
weavers of white satin, the injury done to 
the work is irreparable. In cotton, the 
operation of dressing is indispensable ; in 
silk, this is by no means the case. 
Dressing is justly esteemed of the first 
importance, in the art of weaving warps 
spun from flax or cotton ; for it is impossi- 
ble to produce work of a good quality, un- 
less care be used in dressing the warp. 
The use of dressing is, to give to yarn 
sufficient strength or tenacity, to enable it 
to bear the operation of weaving into cloth. 
It also, by laying smoothly all the ends of 
the fibres, which compose the raw mate- 
rial, from which the yarn is spun, tends 
botir to dituinish the friction during the 
process, and to render the cloth smooth, 
and glossy, when finished. The substance 
in common use. for dressing, is simply a mu- 
cilage of vegetable matter boiled to a con- 
sistency in water. AVheat flour, and some- 
times potatoes, are the substances com- 
monly employed. These answer sufficiently 
well in giving to the yarn both the smooth- 
ness and tenacity required; but the great 
objection to them is, that they are too easily 
and rapidly affected by the operation of 
the atmosphere. When dressed yarn is al- 
lowed to stand exposed to the air, for any 
considerable portion of time, before being 
woven into cloth, it always becomes hard, 
brittle, and comparatively inflexible. It is 
then tedious and troublesome to weave, 
and the cloth is rough, wiry, and uneven. 
This effect is chiefly remarked in dry wea- 
ther, when the weavers of fine cloth find it 
indispensably necessary to have their yarn 
wrought up, as speedily as possible, after 
being dressed. To counteract this incon- 
veniency, herring or beef brine, and other 
saline substances, which have a tendency to 
attract moisture, are sometimes mixed in 
small quantities with the dressing : but this 
lias not proved completely and generally 
successful; probably, because the propor- 
tions have not been sufficiently attended 
to, and because a superabundance of mois- 
ture is eijually prejudicial with a defieieECy. 
Indeed, the variation of the moisture of 
the air is so great and so frequent, that it 
has hitherto been impossible to fix any uni- 
versal rule for the quantity to be mixed. 
It is stated as a fact, which will appear 
singular to weavers in this country, that in 
India the process of weaving, even their 
finest muslins, is conducted in the open air, 
and exposed to all the heat of the climate, 
which is intense. (See Mancfacture of 
Cotton) We, know well that this would 
be impracticable with fine work in this 
country, even in an ordinary summer day. 
It is not known, in this country, what is 
the substance which the Indian weavers 
employ for dressing their wai-ps. It cer- 
tainly would prove of important benefit to 
our manufactures were this investigated in 
a satisfactory manner. 
Neither does it appear that this subject, 
which is of much importance, lias liiUierto 
attracted the attention- ^ scientific men, 
or that it lias been treated in an accurate 
or philosophical manner. It, however, 
opens a wide field for chemical investiga- 
tion, and promises to prove equally useful 
to mankind, and lucrative to the person 
who may succeed in supplying the deside- 
ratum. 
When the warp, previously dressed, lias 
been wiouglit up, as far as can be done 
conveniently, the weaver is obliged to sus- 
pend the operation of weaving, and to pre- 
pare a fresh quantity of warp. It i.s neces- 
sary to stop, when the dressed warp has ap- 
proached within two or three inches of the 
back leaf of the heddles, that room may be 
allowed to join the old dressing to tlie new. 
The first operation, as in wool and silk, is 
to clear the warp, with the comb, from the 
lease rod to the yarn roll, or beam. The ' 
proof that this operation has been properly 
executed is, by bringing back the rods, 
