In this machine, the silk is unwound from the blocks of the
throwing-mill, and formed into hanks for the market. The blocks being of
a large size, would be productive of much friction, if made to revolve
upon skewers thrust through them, and would cause frequent breakage of
the silk. They are, therefore, set with their axes upright upon a board,
and the silk is drawn from their surface, just as the weft is from a cop
in the shuttle. On this account the previous winding-on must be executed
in a very regular manner; and preferably as represented in _fig._ 994.
[Illustration: 998 999]
_Fig._ 998. is a front view of the reel; little more than one-half of it
being shown. _Fig._ 999. is an end view. Here the steam-pulleys are
omitted, for fear of obstructing the view of the more essential parts.
A, A, are the two end framings, connected by mahogany stretchers, which
form the table B, for receiving the bobbins C, C, which are sometimes
weighted at top with a lump of lead, to prevent their tumbling. D is the
reel, consisting of four long laths of wood, which are fixed upon iron
frames, attached to an octagonal wooden shaft. The arm which sustains
one of these laths is capable of being bent inwards, by loosening a
tightening hook, so as to permit the hanks, when finished, to be taken
off, as in every common reel.
The machine consists of two equal parts, coupled together at _a_, to
facilitate the removal of the silk from either half of the reel; the
attendant first lifting the one part, and then the other. E is the guide
bar, which by a traverse motion causes the silk to be wound on in a
cross direction. _b_ and _c_ are the wire guides, and _d_ are little
levers lying upon the cloth-covered guide bar E. The silk in its way
from the block to the reel, passes under these levers, by which it is
cleaned from loose fibres.
On the other end of the shaft of the reel, the spur wheel 1 is fixed,
which derives motion from wheel 2, attached to the shaft of the
steam-pulley F. Upon the same shaft there is a bevel wheel 3, which
impels the wheel 4 upon the shaft _e_; to whose end a plate is attached,
to which the crank _f_ is screwed, in such a way as to give the proper
length of traverse motion to the guide bar E, connected to that crank or
eccentric stud by the jointed rod _g_. Upon the shaft of the
steam-pulleys F, there is a worm or endless screw, to the left of _f_,
_fig._ 999., which works in a wheel 5; attached to the short upright
shaft _h_ (_fig._ 998.). At the end of _h_, there is another worm, which
works in a wheel 6; at whose circumference there is a stud _i_, which
strikes once at every revolution against an arm attached to a bell, seen
to the left of G; thus announcing to the reel-tenter that a measured
length of silk has been wound upon her reel. _e_ is a rod or handle, by
which the fork _l_, with the strap, may be moved upon the fast or loose
pulley, so as to set on or arrest the motion at pleasure.
Throwsters submit their silk to scouring and steaming processes. They
soak the hanks, as imported, in lukewarm soap-water in a tub; but the
bobbins of the twisted single silk from the spinning mill are enclosed
within a wooden chest, and exposed to the opening action of steam for
about ten minutes. They are then immersed in a cistern of warm water,
from which they are transferred to the doubling frame.
The wages of the workpeople in the silk-throwing mills of Italy are
about one half of their wages in Manchester; but this difference is much
more than counterbalanced by the protecting duty of 2_s._ 10_d._ a pound
upon thrown silk, and the superior machinery of our mills. In 1832,
there was a power equal to 342 horses engaged in the silk-throwing mills
of Manchester; and of about 100 in the mills of Derby. The power
employed in the other silk mills of England and Scotland has not been
recorded.
There is a peculiar kind of silk called _marabout_, containing generally
three threads, made from the white Novi raw silk. From its whiteness, it
takes the most lively and delicate colours without the discharge of its
gum. After being made into tram by the single twist upon the spinning
mill, it is reeled into hanks, and sent to the dyer without further
preparation. After being dyed, the throwster re-winds and re-twists it
upon the spinning mill, in order to give it the whipcord hardness which
constitutes the peculiar feature of marabout. The cost of the raw Novi
silk is 19_s._ 6_d._ a pound; of throwing it into tram, 2_s._ 6_d._; of
dyeing, 2_s._; of re-winding and re-twisting, after it has been dyed,
about 5_s._; of waste, 2_s._, or 10 per cent.; the total of which sum is
31_s._; being the price of one pound of marabout in 1832.
An ESTIMATE of the Annual Quantities of SILK produced or exported from
the several Countries in the World, exhibiting also the Countries to
which exported.
+-------------------+---------------------------+------------+------+
|Countries whence |Quantities. |Countries to|Quan- |
|exported. | |which ex- |ti- |
| | |ported. |ties. |
+-------------------+---------------------------+------------+------+
| | | |Bales.|
|Italy exports |34,000 bales of 225 small | | |
| | lbs. | | |
|France produces |10,500 { 73-1/8 kils., or |}England |28,000|
|India and Bengal | 9,500 {128-1/2 Vienna lbs.|}France |22,000|
| export | 162 lbs. English | | |
|Persia . . | 7,500 |Prussia | 7,600|
|China . . | 4,000 |Russia | 6,400|
|Asia Minor . . | 3,500 |Austria and | |
|Levant, Turkey, and| |Germany | 5,000|
|Archipelago export | 3,500 |Switzerland | 5,000|
|Spain . . | 1,500 | |------|
| |------ |Total |74,000|
|Total |74,000 bales. | | |
+-------------------+---------------------------+------------+------+
_Note._--These estimates exclude the silk manufactured in Italy.
The declared value of the silk manufactures exported from the United
Kingdom in 1836, was 917,822_l._; and in 1837, only 494,569. The deficit
in the last year was owing to the commercial crisis in the United
States; which country took, the preceding year, our silk goods to the
value of 524,301_l._
[Illustration: 1000]
SILKWORM GUT, for angling, is made as follows:--Select a number of the
best and largest silkworms, just when they are beginning to spin; which
is known by their refusing to eat, and having a fine silk thread hanging
from their mouths. Immerse them in strong vinegar, and cover them
closely for twelve hours, if the weather be warm, but two or three hours
longer, if it be cool. When taken out, and pulled asunder, two
transparent guts will be observed, of a yellow green colour, as thick as
a small straw, bent double. The rest of the entrails resembles boiled
spinage, and therefore can occasion no mistake as to the silk-gut. If
this be soft, or break upon stretching it, it is a proof that the worm
has not been long enough under the influence of the vinegar. When the
gut is fit to draw out, the one end of it is to be dipped into the
vinegar, and the other end is to be stretched gently to the proper
length. When thus drawn out, it must be kept extended on a thin piece of
board, by putting its extremities into slits in the end of the wood, or
fastening them to pins, and then exposed in the sun to dry. Thus genuine
silk-gut is made in Spain. From the manner in which it is dried, the
ends are always more or less compressed or attenuated.[53] _Fig._ 1000.
_a_, is the silkworm; _b_, the worm torn asunder; _c_, _c_, the guts;
_d_, _d_, a board slit at the ends, with the gut to dry; _f_, _f_, a
board with wooden pegs, for the same purpose.
[53] Nobb’s Art of Trolling.
SILVER (_Argent_, Fr.; _Silber_, Germ.;) was formerly called a _perfect_
metal, because heat alone revived its oxide, and because it could pass
unchanged through fiery trials, which apparently destroyed most other
metals. The distinctions, perfect, imperfect, and noble, are now justly
rejected. The bodies of this class are all equal in metallic nature,
each being endowed merely with different relations to other forms of
matter, which serve to characterize it, and to give it a peculiar value.
When pure and planished, silver is the brightest of the metals. Its
specific gravity in the ingot is 10·47; but, when condensed under the
hammer or in the coining press, it becomes 10·6. It melts at a bright
red heat, a temperature estimated by some as equal to 1280° Fahr., and
by others to 22° Wedgewood. It is exceedingly malleable and ductile;
affording leaves not more than 1/100000 of an inch thick, and wire far
finer than a human hair.
By Sickingen’s experiments, its tenacity is, to that of gold and
platinum, as the numbers 19, 15, and 26-1/4; so that it has an
intermediate strength between these two metals. Pure atmospheric air
does not affect silver, but that of houses impregnated with sulphuretted
hydrogen, soon tarnishes it with a film of brown sulphuret. It is
distinguished chemically from gold and platinum by its ready solubility
in nitric acid, and from almost all other metals, by its saline
solutions affording a curdy precipitate with a most minute quantity of
sea salt, or any soluble chloride.