+---------------------+----------------------+-----------+
| Iron Cables. | Hemp Cables. |Resistance.|
|Diameter of Iron Rod.|Circumference of Rope.| |
+---------------------+----------------------+-----------+
| _Inches._ | _Inches._ | _Tons._ |
| 0-7/8 | 9 | 12 |
| 1 | 10 | 18 |
| 1-1/8 | 11 | 26 |
| 1-1/4 | 12 | 32 |
| 1-5/16 | 13 | 35 |
| 1-3/8 | 14 to 15 | 38 |
| 1-1/2 | 16 | 44 |
| 1-5/8 | 17 | 52 |
| 1-3/4 | 18 | 60 |
| 1-7/8 | 20 | 70 |
| 2 | 22 to 24 | 80 |
+---------------------+----------------------+-----------+
It would be imprudent to put hemp cables to severer strains than those
indicated in the preceding table, drawn up from Brunton’s experiments;
but the iron cables of the above sizes will support a double strain
without breaking. They ought never in common cases however to be exposed
to a greater stress. A cable destined for ships of a certain tonnage,
should not be employed in those of greater burden. Thus treated it may
be always trusted to do its duty, and will last longer than the ship to
which it belongs. A considerable part of this decided superiority which
iron cables have over hemp ones, is undoubtedly due to the admirable
form contrived by Brunton. Repeated experiments have proved that his
cables possess double the strength of the iron rods with which they are
made--a fact which demonstrates that no stronger form can be devised or
is in fact possible.
One of the most valuable qualities of iron cables is their resisting
lateral as well as longitudinal strains as explained under _figs._ 219.
and 221.
Vessels furnished with such cables have been saved by them from the most
imminent peril. The Henry, sent out with army stores during the
peninsular war, was caught on the northern coast of Spain in a furious
storm. She run for shelter into the Bay of Biscay among the rocks, where
she was exposed for three days to the hurricane. She possessed
fortunately one of Brunton’s 70 fathom chain cables, which held good all
the time, but it was found afterwards to have had the links of its lower
portion polished bright by attrition against the rocky bottom. A hemp
cable would have been speedily torn to pieces in such a predicament.
In the contracts of the Admiralty for chain cables for the British navy,
it is stipulated that “the iron shall have been manufactured in the best
manner from pig iron, smelted from iron-stone only, and selected of the
best quality for the purpose, and shall not have received in any process
whatever subsequent to the smelting, the admixture of either the cinder
or oxides produced in the manufacture of iron; and shall also have been
puddled in the best manner upon iron bottoms, and at least three times
sufficiently drawn out at three distinct welding heats, and at least
twice properly fagotted.”
The following is a table of the breaking proof of chain cables, and of
the iron for the purpose of making them, also of the proofs required by
her majesty’s navy for chains.
+-------------+--------------+---------------+--------------------+
|Size of Bolt.|Proof of Bolt.|Proof of Chain.|Navy Proof of Chain.|
+-------------+--------------+---------------+--------------------+
| _Inches._ |_Tons._ _Cwt._|_Tons._ _Cwt._ | _Tons._ |
| 1/2 | 5 7 | 8 11 | 4-1/2 |
| 5/8 | 8 7 | 13 4 | 5-1/2 |
| 3/4 | 12 1 | 19 5 | 10-7/8 |
| 7/8 | 16 4 | 26 5 | 13-3/4 |
| 1 | 21 8 | 34 5 | 18 |
| 1-1/8 | 27 2 | 48 15 | 22-3/4 |
| 1-1/4 | 33 10 | 53 11 | 28-1/2 |
| 1-3/8 | 40 10 | 65 0 | 34 |
| 1-1/2 | 48 4 | 77 0 | 40-1/2 |
| 1-5/8 | 56 11 | 90 10 | 47-1/2 |
| 1-3/4 | 65 12 | 105 0 | 55-1/8 |
| 1-7/8 | 75 6 | 120 10 | 63-1/4 |
| 2 | 85 14 | 137 0 | 72 |
| 2-1/8 | 96 15 | 155 0 | 81-1/4 |
+-------------+--------------+---------------+--------------------+
In Brunton’s cable the matter in the link is thrown very much into one
plane; the link being of an oval form, and provided with a stay. As
there are emergencies in which the cable must be severed, this is
accomplished in those of iron by means of a bolt and sheckle (shackle),
at every fathom or two fathoms; so that by striking out this bolt or
pin, this cable is parted with more ease than a hempen one can be cut.
CACAO, BUTTER OF. See COCOA, and OILS, UNCTUOUS.
CADMIUM, is a metal discovered about the beginning of the year 1818. It
occurs chiefly in Silesia in several ores of zinc; and may be readily
recognized by means of the blowpipe; for at the first impression of the
reducing or smoky part of the flame, the ores containing cadmium stain
the charcoal all round them with a reddish yellow circle of oxide of
cadmium. The Silesian native oxide of zinc contains from 1-1/2 to 11 per
cent. of cadmium.
The cadmium may be extracted by dissolving the ore in sulphuric acid,
leaving the solution acidulous, and diluting it with water, then
transmitting through it a stream of sulphuretted hydrogen, till the
yellow precipitate ceases to fall. This powder which is sulphuret of
cadmium, is to be dissolved in concentrated muriatic acid, the excess of
which is to be expelled by evaporation; and the muriatic salt being
dissolved in water, carbonate of ammonia is to be added in excess,
whereby the cadmium separates as a carbonate, while the small portion of
adhering copper or zinc is retained in solution by the ammonia. Herapath
has shown that, in distilling zinc _per descensum_ (see ZINC), the first
portions of gaseous metal which are disengaged burn with a brown flame
and deposit the brown oxide of cadmium.
Cadmium has the colour and lustre of tin; and is susceptible of a fine
polish. Its fracture is fibrous; it crystallizes readily in regular
octahedrons, and when it suddenly solidifies, its surface gets covered
with fine mossy vegetations. It is soft, easily bent, filed, and cut,
soils like lead any surface rubbed with it. It is harder and more
tenacious than tin, and emits a creaking sound when bent, like that
metal. It is very ductile, and may be drawn out into fine wire, and
hammered into thin leaves without cracking at the edges. Its specific
gravity, after being merely melted, is 8·604; and 8·6944 after it has
been hammered. It is very fusible, melting at a heat much under redness;
indeed at a temperature little exceeding that of boiling mercury, it
boils and distils over in drops. Its vapours have no smell. It is but
slightly altered by exposure to air. When heated in the atmosphere, it
readily takes fire, and burns with a brownish yellow smoke which is
destitute of smell. In strong acids it dissolves with disengagement of
hydrogen, and forms colourless solutions. Chromate of potash causes no
precipitate in them, unless zinc or lead be present.
There is only one oxide of cadmium, the brown above-mentioned. Its
specific gravity is 8·183. It is neither fusible nor volatile at a very
high temperature. When in the state of a hydrate it is white. The oxide
of cadmium consists of 87·45 parts of metal, and 12·55 oxygen in 100
parts. Berzelius states its atomic weight to be 55·833 to hydrogen
1·000. Its sulphuret has a fine orange yellow colour, and would form a
beautiful pigment, could the metal be found in sufficient quantity for
the purposes of art. The sulphate is applied to the eyes by surgeons for
removing specks of the cornea.
CAFEINE. A chemical principle discovered in coffee, remarkable for
containing much azote. See COFFEE.
CAJEPUT OIL is obtained from the leaves of the tree called Melaleuca
Leucadendron by Linnæus, which grows upon the mountains of Amboyna, and
in other of the Molucca islands. It is procured by distillation of the
dried leaves along with water, is prepared in great quantities in the
island of Banda, and sent to Holland in copper flasks. Hence as it comes
to us, it has a green colour. It is very limpid, lighter than water, of
a strong smell resembling camphor, and pungent taste like cardamoms.
When rectified the copper remains in the retort, and the oil comes over
colourless. It is used in medicine as a stimulant. See OILS ETHEREOUS.
CALAMANCO. A sort of woollen stuff of a shining appearance, chequered in
the warp, so that the checks are seen only upon one side.
CALAMINE. A native carbonate of zinc. See ZINC.
CALCAREOUS EARTH. (_Terre calcaire_, Fr.; _Kalkerde_, Germ.) Commonly
denotes lime, in any form; but, properly speaking, it is pure lime.
CALCAREOUS SPAR. Crystallized native carbonate of lime.
CALCEDONY. A hard mineral of the siliceous family, often cut into seals.
Under it may be grouped common calcedony, heliotrope, chrysoprase,
plasma, onyx, sardonyx, and sard.
CALCHANTUM. The ancient name of native copperas or sulphate of iron.
CALCINATION, is the chemical process of subjecting metallic bodies to
heat with access of air, whereby they are converted into a pulverulent
matter, somewhat like lime in appearance, called _calx_ in Latin. The
term calcination, however, is now used when any substance whatever is
exposed to a roasting heat.
CALCIUM. The metallic basis of lime. See LIME.
CALC-SINTER. The incrustations of carbonate of lime upon the ground, or
the pendulous conical pieces called stalactites, attached to the roofs
of caverns, are so called.
CALC-TUFF. A semi-hard irregular deposit of carbonate of lime, formed
from the waters of calcareous springs.
CALCULUS. The stony-looking morbid concretion, occasionally formed in
the bladder of urine, gall-bladder, cystic duct, kidneys, and other
parts of living animals. Its examination belongs to medical chemistry.
CALENDER, (_Calandre_, Fr.; _Kalander_, Germ.) a word derived from the
Greek _kalindros_ (cylinder), is the name of a machine, consisting of
two or more cylinders, revolving so nearly in contact with each other
that cloth passed through between them is smoothed, and even glazed, by
their powerful pressure. It is employed either to finish goods for the
market, or to prepare cotton and linen webs for the calico-printer, by
rendering their surfaces level, compact, and uniform. This condensation
and polish, or _satinage_, as the French call it, differ in degree
according to the object in view, and may be arranged into three distinct
series. 1. For goods which are to receive the first impression by the
block, a very strong pressure is required; for, upon the uniformity of
the polish, the neatness and regularity of the printing, and the
correspondence of its members, depend. In many establishments the calico
is passed twice through the calender before being sent to the tables. 2.
The pieces already dyed up at the madder bath, or otherwise, and which
remain to be filled in with other colours, or _grounded-in_, as it is
technically styled, must receive a much less considerable gloss. This is
a principle every where admitted and acted upon, because the outline of
the figured design being deranged by the washing, and sometimes in
consequence of the peculiar texture of the cloth, the printer, in order
to apply his grounding blocks properly, and to fit them to the contours
of the figures already impressed, is obliged to stretch the piece
sometimes in the direction of the warp, and sometimes of the weft, which
would be impossible if they had been hard glazed by the calender. 3. The
degree of glazing given to finished goods depends upon the taste of
purchasers, and the nature of the article; but it is, in general, much
less than for the first course of block-printing.
The most complete calender probably in existence is that used by some of
the eminent calico-printers of Alsace, as contrived by M. Charles
Dollfus, and constructed by MM. Witz, Blech, and Co. 1. It passes two
pieces at once, and thus does double the work of any ordinary machine.
2. It supersedes the necessity of having a workman to fold up the goods,
as they emerge from the calender, with the aid of a self-acting folder.
3. It receives, at pleasure, the finished pieces upon a roller, instead
of laying them in folds; and, by a very simple arrangement, it hinders
the hands of the workmen from being caught by the rollers.
Calenders, in consequence of the irregular demand for foreign orders and
shipments, are worked very irregularly, being sometimes overloaded with
duty, and at others altogether unemployed. A machine which can, when
required, turn out a double quantity of goods must, therefore, be a
desirable possession. For the first course of the printers, where high
calendering is necessary, the goods are usually passed twice through
between two paper cylinders, to give that equality of surface which
could not be obtained by one passage, however strong the pressure; and
therefore the simplification of this calender will prove no economy.
Besides, in order to increase the pressure to the requisite degree, the
cylinders would need to be made bulging at their middle part, and with
such cylinders common smoothing could not be given; for the pieces would
be glazed in the central line, and rough towards the edges. For pieces
already printed in part, and requiring only to be grounded-in for other
colours, the system of double effect has fewer objections, as a single
passage through the excellent calender described under BLEACHING, page
134., is found to answer very well.
The most remarkable feature of M. Dollfus’s machine is its being managed
by a single workman. Six or eight pieces are coiled upon the
feed-roller, and they are neither pasted nor stitched together, but the
ends are merely overlapped half a yard or so. The workman is careful not
to enter the second piece till one third or one half of the first one
has passed through on the other side, to prevent his being engrossed
with two ends at a time. He must, no doubt, go sometimes to the one side
and sometimes to the other of the machine to see that no folds or
creases occur, and to be ready for supplying a fresh piece as the
preceding one has gone through. The mechanism of the folder in the
Alsace machine is truly ingenious: it performs extremely well, really
saves the attendance of an extra workman, and is worthy the attention of
manufacturers intent upon economising hand labour. The lapping-roller
works by friction, and does its duty fully better than similar machines
guided by the hand.
The numerous accidents which have happened to the hands of workmen
engaged in calenders should direct the attention towards its effective
contrivance for preventing such misfortunes. These various improvements
in the Alsace machine may be easily adapted to the ordinary calenders of
almost every construction.
The folder is a kind of cage, in the shape of an inverted pyramid, shut
on the four sides, and open at top and bottom: the top orifice is about
five inches, the bottom one an inch and a half: the front and the back,
which are about four feet broad, are made of tin-plate or smooth
pasteboard, and the two sides are made of strong sheet-iron; the whole
being bolted together by small bars of iron. Upon the sheet-iron of the
sides, iron uprights are fixed, perforated with holes, through which the
whole cage is supported freely by means of studs that enter into them.
One of the uprights is longer than the other, and bears a slot with a
small knob, which, by means of the iron piece, joins the guide to the
crank of the cylinder, and thereby communicates to the cage a seesaw
movement: at the bottom extremity of the great upright, there is a piece
of iron in the shape of an anchor, which may be raised, or lowered, or
made fast, by screws.
At the ends of this anchor are friction-rollers, which may be drawn out
or pushed back and fixed by screws: these rollers lift alternately two
levers made of wood, and fixed to a wooden shaft.
The paws are also made of wood: they serve to lay down alternately the
plies of the cloth which passes upon the cage, and is folded zigzag upon
the floor, or upon a board set below the cage: a motion imparted by the
seesaw motion of the cage itself. See STRETCHING MACHINE.
To protect the fingers of the workmen, above the small plate of the
spreading-board or bar, there is another bar, which forms with the
former an angle of about 75°: they come sufficiently near together for
the opening at the summit of the angle to allow the cloth to pass
through, but not the fingers. See _Bulletin de la Société Industrielle
de Mulhausen_, No. 18.
I shall now describe, more minutely, the structure of the powerful but
less complicated calender mechanisms employed in the British
manufactories.
[Illustration: 228 229 230]
A front elevation of a four-rollered calender (five rollers are often
introduced) for glazing goods is given in _fig._ 228. _d l_ are two
pasteboard or paper cylinders, each 20 inches in diameter, whose
structure will be presently described: _f_ is a cast-iron cylinder
turned perfectly smooth (its fellow is often placed between _e_ and
_d_): it is eight inches in diameter outside, four inches inside, with
two inches thickness of metal. _e_ is another pasteboard cylinder,
fourteen inches in diameter: the strong cast-iron frame contains the
bushes in which the journals of the rollers turn. _o p_, is one of the
pair of levers for communicating a graduated pressure according to the
quality of the goods. _Fig._ 229, 230. are end views of the same machine
to show the working geer. The wheel _s_, on the end of the upper iron
cylinder, is ten inches in diameter; that on the end of the fellow iron
cylinder below (when it is present) is thirteen inches; both are
connected by the larger carrier wheel _t_. The lower wheel _u_ is one
third larger than the upper wheel, and therefore receives from the
carrier wheel _t_, a proportionally slower motion, which it imparts to
the central pasteboard roller _e_, lying upon it, causing it to move one
third more slowly than the upper pasteboard roller. Thus a sort of
sliding motion is produced, which, by rubbing their surfaces, glazes the
goods.
The iron rollers are made hollow for the purpose of admitting either a
hot roller of iron, or steam when hot calendering is required. The
other cylinders used formerly to be made of wood, but it was liable to
many defects. The advantage of the paper roller consists in its being
devoid of any tendency to split, crack, or warp, especially when exposed
to a considerable heat from the contact and pressure of the hot iron
rollers. The paper, moreover, takes a vastly finer polish, and, being of
an elastic nature, presses into every pore of the cloth, and smooths its
surface more effectually than any wooden cylinder, however truly turned,
could possibly do.
The paper cylinder is constructed as follows:--The axis of the cylinder
is a strong square bar of the best wrought iron, cut to the proper
length. Upon this bar a strong round plate of cast iron is first put,
somewhat less in diameter than the cylinder when finished. A quantity of
thick stout pasteboard is then procured, and cut into round pieces an
inch larger in diameter than the iron plate. In the centre of the
plates, and of every piece of the pasteboard, a square hole must be cut
to receive the axis; and, the circle being divided into six equal parts,
a hole must also be cut at each of the divisions, an inch or two within
the rim. These pieces of pasteboard being successively put upon the
axis, a long bolt of malleable iron, with a head at one end, and screwed
at the other, is also introduced through each of the holes near the rim;
and this is continued until a sufficient number of pasteboards are thus
placed to form a cylinder of the length required, proper allowance being
made for the compression which the pasteboard is afterwards to undergo.
Another round plate is then applied, and, nuts being put upon the
screws, the whole are screwed tight, and a cylinder formed. This
cylinder is now to be placed in a stove, exposed to a strong heat, and
must be kept there for at least several days; and, as the pasteboard
shrinks by exposure to the heat, the screws must be frequently tightened
until the whole mass has been compressed as much as possible. When the
cylinder is thus brought to a sufficient degree of density it is removed
from the stove; and, when allowed to cool, the pasteboard forms a
substance almost inconceivably dense and hard. Nothing now remains but
to turn the cylinder; and this is an operation of no slight labour and
patience. The motion in turning must be slow, not exceeding about forty
revolutions in a minute; the substance being now so hard and tough that
tools of a very small size must be used to cut, or rather scrape it,
until it is true. Three men are generally employed for the turning, even
when the motion of the cylinder is effected by mechanical power, two
being necessary to sharpen tools, for the third who turns, as quickly as
he blunts them.
Let us suppose it to be a five-rollered machine: when a person stands in
front of the calender, the cloth coming from behind above the uppermost
cylinder 1, passes between 1 and 2: proceeding behind 2, it again comes
to the front between 2 and 3: between 3 and 4 it is once more carried
behind, and, lastly, brought in front between 4 and 5, where it is
received, and smoothly folded on a clean board, or in a box, by a person
placed there for the purpose. In folding the cloth at this time, care
must be taken that it may be loosely done, so that no mark may appear
until it be again folded in the precise length and form into which the
piece is to be made up. The folding may be done either by two persons or
by one, with the aid of two sharp polished spikes placed at a proper
distance, to ascertain the length of the fold, and to make the whole
equal. When folded into lengths, it is again folded across upon a smooth
clean table, according to the shape intended, which varies with the
different kinds of goods, or the particular market for which the goods
are designed.
When the pieces have received the proper fold, the last operation
previous to packing them is the pressing. This is commonly performed by
placing a certain number of pieces, divided by thin smooth boards of
wood, in a common screw press, similar to those used by printers for
taking out the impression left by the types in the printing-press.
Besides the wooden boards, a piece of glazed pasteboard is placed above
and below every piece of cloth, that the outer folds may be as smooth
and glossy as possible. The operation of the common screw press being
found tedious and laborious, the hydraulic press is now in all well
mounted establishments had recourse to. See HYDRAULIC PRESS.
No improvements that have taken place in calendering can exceed the
power and facility of the water press: one of these presses may be
worked by two men, who can with great ease produce a pressure of 400
tons; but, in considerable establishments, the presses are worked by
power. See BANDANNA.
The appearance and finish of the goods, in consequence of such an
immense weight acting on them, are materially improved.
The press is also used for the purpose of packing; whereby the bale is
rendered much more compact than formerly. It is commonly roped, &c.,
while in this compressed state; the dimensions, are therefore, greatly
diminished from what they would otherwise be by any other method. For
instance, the same quantity of goods packed in a bale are from one third
to one half less bulky than if they were packed in a box with the utmost
force of the hands.
For lawns and muslins of a light texture, the operation of smoothing
requires a different process in some respects than close heavy fabrics.
They only require to be slightly smoothed to remove any marks which they
may have received at the bleaching; and, as their beauty depends rather
on their transparency than their closeness, the more the cylindrical
form of the yarn is preserved the better. They are therefore put through
a small machine, consisting of three rollers or cylinders; and, as the
power required to move this is small, the person who attends it
generally drives it by a small winch; or the same effect may be produced
by passing the muslins between only two or three rollers of the above
calender, lightly loaded.
In the thick fabrics of cloth, including those kinds which are used for
many parts of household furniture, as also those for female dress, the
operation of glazing is used both to add to the original beauty of the
cloth, and to render it more impervious to dust or smoke. The glazing
operation is performed entirely by the friction of any smooth substance
upon the cloth; and, to render the gloss brighter, a small quantity of
bleached wax is previously rubbed over the surface. The operation of
glazing by the common plan is very laborious, but the apparatus is of
the most simple kind. A table is mounted with a thick stout cover of
level and well-smoothed wood, forming an inclined plane; that side where
the operator stands at work being the lowest. The table is generally
placed near a wall, both for convenience in suspending the glazing
apparatus, and for the sake of light. A long piece of wood is suspended
in a groove formed between two longitudinal beams, placed parallel to
the wall, and fixed to it. The groove resembles exactly the aperture
between the shears of a common turning lathe. The lever, of which the
groove may be supposed to be the centre or fulcrum, is faced at the
bottom with a semi-cylindrical piece of finely polished flint, which
gives the friction to the cloth stretched upon the table below. Above
the flint are two cross handles, of which the operator lays hold, and
moves them backward and forward with his hands, keeping the flint
pressing slightly upon the cloth. When he has glazed a portion equal to
the breadth of the flint, he moves his lever between the shears
sidewise, and glazes a fresh part: thus he proceeds from one side or
selvage of the cloth to the other: and when all which is upon the table
is sufficiently glazed, he draws it over, and exposes a new portion to
the same operation. To preserve the cloth at a proper tension, it may be
wound smoothly upon a roller or beam, which being set so as to revolve
upon its own axis behind the table, another roller to receive the cloth
may be placed before, both being secured by a catch, acting in a ratchet
wheel. Of late years, however, a great part of the labour employed in
glazing cloth has been saved, as the common four or five bowl calender
has been altered to fit this purpose by direct pressure.
As a matter of accommodation, the different processes of packing,
cording of boxes, sheeting of trunks, and, in general, all the
arrangements preparatory to shipments, and also the intimations and
surveys necessary for obtaining drawbacks, debentures, or bounties,
according to the excise laws, are generally conducted at the calender
houses where goods are finished. These operations sufficiently account
for the general meaning attached to the word.
CALICO-PRINTING (_Impression d’Indiennes_, Fr.; _Zeugdruckerei_, Germ.)
is the art of impressing cotton cloth with topical dyes of more or less
permanence. Of late years, silk and woollen fabrics have been made the
subjects of a similar style of dyeing. Linens were formerly stained with
various coloured designs, but since the modern improvements in the
manufacture of cotton cloth they are seldom printed, as they are both
dearer, and produce less beautiful work, because flax possesses less
affinity than cotton for colouring matters.
This art is of very ancient date in India, and takes its English name
from Calicut, a district where it has been practised with great success
from time immemorial. The Egyptians, also, appear from Pliny’s testimony
to have practised at a remote era some of the most refined processes of
topical dyeing. “Robes and white veils,” says he, “are painted in Egypt
in a wonderful way. They are first imbued, not with dyes, but with
dye-absorbing drugs, by which, though they seem to be unaltered, yet,
when immersed for a little while in a cauldron of the boiling
dye-liquor, they are found to become painted. Yet, as there is only one
colour in the cauldron, it is marvellous to see many colours imparted to
the robe, in consequence of the influence of the excipient drug. Nor can
the dye be washed out. A cauldron, which would of itself merely confuse
the colours of cloths previously dyed, is thus made to impart several
pigments from a single dye-stuff, _painting as it boils_.” The last
expression _pingitque dum coquit_, is perfectly graphic and descriptive
of calico-printing.
The cotton chintz counterpanes of great size, called _pallampoors_,
which have been manufactured in Madras from the earliest ages, have in
like manner peculiar dye-absorbing drugs applied to them with the
pencil, as also wax, to protect certain parts of the surface from the
action of the dye, and are afterwards immersed in a staining liquor,
which, when wax is applied, is usually the cold indigo-vat, but without
the wax is a hot liquor similar to the Egyptian. M. Koechlin Roder, of
Mulhouse, brought home lately from India a rich collection of cloths in
this state of preparation, which I saw in the cabinet of the _Société
Industrielle_ of that interesting emporium of calico-printing. The
native implements for applying the wax and colouring bases are placed
alongside of the cloths, and form a curious picture of primeval art.
There is among other samples an ancient _pallampoor_, five French yards
long, and two and a half broad, said to be the labour of Hindoo
princesses, which must have taken a lifetime to execute. The printing
machinery of great Britain has begun to supersede, for these styles of
work, the cheapest hand labour of India.
Calico-printing has been for several hundred years practised by the
oriental methods in Asia Minor and the Levant, but it was unknown as an
English art till 1696, when a small print-ground was formed upon the
banks of the Thames, near Richmond, by a Frenchman; probably a refugee
from his own country, in consequence of the revocation of the edict of
Nantes. Some time afterwards, a considerable printing work was
established at Bromley Hall, in Essex, and several others sprung up
successively in Surrey, to supply the London shops with chintzes, their
import from India having been prohibited by act of parliament in 1700.
The silk and woollen weavers, indeed, had all along manifested the
keenest hostility to the use of printed calicoes, whether brought from
the East or made at home. In the year 1680 they mobbed the India House
in revenge for some large importations then made of the chintzes of
Malabar. They next induced the government, by incessant clamours, to
exclude altogether the beautiful robes of Calicut from the British
market. But the printed goods, imported by the English and Dutch East
India companies, found their way into this country, in spite of the
excessive penalties annexed to smuggling, and raised a new alarm among
the manufacturing population of Spitalfields. The sapient legislators of
that day, intimidated, as would appear, by the East London mobs, enacted
in 1720 an absurd sumptuary law, prohibiting the _wearing of all printed
calicoes whatsoever, either of foreign or domestic origin_. This
disgraceful enactment, worthy of the meridian of Cairo or Algiers,
proved not only a death blow to rising industry in this ingenious
department of the arts, but prevented the British ladies from attiring
themselves in the becoming drapery of Hindostan. After an oppressive
operation of ten years, this act was repealed by a partially enlightened
set of senators, who were then pleased to permit what they called
British calicoes, if made of linen warp, with merely weft of the _hated_
cotton, to be printed and worn, upon paying a duty of no less than
sixpence the square yard. Under this burden, English calico-printing
could not be expected to make a rapid progress. Accordingly, even so
lately as the year 1750, no more than 50,000 pieces of mixed stuff were
printed in Great Britain, and that chiefly in the neighbourhood of
London; whereas a single manufacturer, Mr. Coates of Manchester,
now-a-days will turn off nearly twenty times that quantity, and there
are very many others who manufacture several hundred thousand pieces per
annum. It was not till about 1766 that this art migrated into
Lancashire, where it has since taken such extraordinary development; but
it was only after 1774 that it began to be founded upon right
principles, in consequence of the repeal of that part of the act of 1730
which required the warp to be made of linen yarn. Henceforth the
printer, though still saddled with a heavy duty of 3_d._ the square
yard, was allowed to apply his colours to a homogeneous web, instead of
the mixed fabric of linen and cotton substances, which differ in their
affinities for dyes.
France pursued for some time a similar false policy with regard to
calico-printing, but she emerged sooner from the mists of manufacturing
monopoly than England. Her avowed motive was to cherish the manufacture
of flax, a native product, instead of that of cotton, a raw material,
for which prejudice urged that money had to be exported. Her intelligent
statesmen of that day, fully seventy years ago, replied, that the money
expended in the purchase of cotton was the produce of French industry,
beneficially employed, and they therefore took immediate measures to put
the cotton fabrics upon a footing of equality. Meanwhile the popular
prejudices became irritated to such a degree, by the project of
permitting the free manufacture and sale of printed cottons, that every
French town possessed of a chamber of commerce made the strongest
remonstrances against it. The Rouen deputies declared to the government,
“that the intended measure would throw its inhabitants into despair, and
make a desert of the surrounding country;” those of Lyons said, “the
news had spread terror through all its work-shops:” Tours “foresaw a
commotion likely to convulse the body of the state:” Amiens said, “that
the new law would be the grave of the manufacturing industry of France;”
and Paris declared that “her merchants came forward to bathe the throne
with their tears upon that inauspicious occasion.”
The government persisted in carrying its truly enlightened principles
into effect, and with so manifest advantage to the nation, as to warrant
the inspector-general of manufactures to make, soon afterwards, the
following appeal to those prejudiced bodies:--“Will any of you now deny
that the fabrication of printed cottons has occasioned a vast extension
of the industry of France, by giving profitable employment to a great
many hands in spinning, weaving, bleaching, and printing the colours?
Look only at the dyeing department, and say whether it has not done more
good to France in a few years than many of your other manufactures have
in a century?”
The despair of Rouen has been replaced by the most signal prosperity in
the cotton trade, and especially in printed calicoes, for the
manufacture of which it possesses 70 different establishments, producing
upwards of a million of pieces of greater average size and price than
the English. In the district of the Lower Seine, round that town, there
are 500 cotton factories of different kinds, which give employment to
118 thousand operatives of all orders, and thus procure a comfortable
livelihood to probably not less than half a million of people.
The repeal, in 1831, of the consolidated duty of 3-1/2_d._ per square
yard upon printed calicoes in Great Britain is one of the most judicious
acts of modern legislation. By the improvements in calico-printing, due
to the modern discoveries and inventions in chemistry and mechanics, the
trade had become so vast as to yield in 1830 a revenue of 2,280,000_l._
levied upon 8,596,000 of pieces, of which, however, about three fourths
were exported, with a drawback of 1,579,000_l._ 2,281,512 pieces were
consumed in that year at home. When the expenses of collection were
deducted, only 350,000_l._ found their way into the exchequer, for which
pitiful sum thousands of frauds and obstructions were committed against
the honest manufacturer. This reduction of duty enables the consumer to
get this extensive article of clothing from 50 to 80 per cent. cheaper
than before, and thus places a becoming dress within the reach of
thousands of handsome females in the humbler ranks of life. Printed
goods, which in 1795 were sold for two shillings and three-pence the
yard, may be bought at present for eight-pence. In fact a woman may now
purchase the materials of a pretty gown for two shillings. The repeal of
the tax has been no less beneficial to the fair dealers, by putting an
end to the contraband trade, formerly pursued to an extent equally
injurious to them and the revenue. It has, moreover, emancipated a
manufacture, eminently dependent upon taste, science, and dexterity,
from the venal curiosity of petty excisemen, by whom private
improvements, of great value to the inventor, were in perpetual jeopardy
of being pirated and sold to any sordid rival. The manufacturer has now
become a free agent, a master of his time, his workmen, and his
apparatus; and can print at whatever hour he may receive an order;
whereas he was formerly obliged to wait the convenience of the excise
officer, whose province it was to measure and stamp the cloth before it
could be packed,--an operation fraught with no little annoyance and
delay. Under the patronage of parliament, it was easy for needy
adventurers to buy printed calicoes, because they could raise such a sum
by drawbacks upon the export of one lot as would go far to pay for
another, and thus carry on a fraudulent system of credit, which sooner
or later merged in a disastrous bankruptcy. Meanwhile the goods thus
obtained were pushed off to some foreign markets, for which they were,
possibly, not suited, or where they produced, by their forced sales a
depreciation of all similar merchandize, ruinous to them and who meant
to pay for his wares.
The principles of calico-printing have been very profoundly studied by
many of the French manufacturers, who generally keep a chemist, who has
been educated in the Parisian schools of science, constantly at work,
making experiments upon colours in a well-mounted laboratory. In that
belonging to M. Daniel Kœchlin, of Mulhausen, there are upwards of 3000
labelled phials, filled with chemical reagents, and specimens
subservient to dyeing. The great disadvantage under which the French
printers labour is the higher price they pay for cotton fabrics, above
that paid by the English printers. It is this circumstance alone which
prevents them from becoming very formidable rivals to us in the markets
of the world. M. Barbet, deputy and mayor of Rouen, in his replies to
the ministerial commission of inquiry, rates the disadvantage proceeding
from that cause at 2 francs per piece, or about 5 per cent. in value. In
the annual report of the _Société Industrielle_ of Mulhausen, made in
December, 1833, the number of pieces printed that year in Alsace is
rated at 720,000, to which if we add 1,000,000 for the produce of the
department of the Lower Seine, and 280,000 for that of St. Quentin,
Lille, and the rest of France, we shall have for the total amount of
this manufacture 2,000,000 of pieces, equivalent to nearly 2,400,000
pieces English; for the French piece usually measures 33-1/2 aunes, = 41
yards nearly; and it is also considerably broader than the English
pieces upon an average. It is therefore probable that the home
consumption of France in printed goods is equal in quantity, and
superior in value, to that of England. With regard to the comparative
skill of the workmen in the two countries, M. Nicholas Kœchlin, deputy
of the Upper Rhine, says, that one of his foremen, who worked for a year
in a print-field in Lancashire, found little or no difference between
them in that respect. The English wages are considerably higher than the
French. The machines for multiplying production, which for some time
gave us a decided advantage, are now getting into very general use among
our neighbours. In my recent visit to Mulhausen, Rouen, and their
environs, I had an opportunity of seeing many printing establishments
mounted with all the resources of the most refined mechanisms.
The calico-printing of this country still labours under the burden of
considerable taxes upon madder and gallipoli oil, which have
counteracted the prosperity of our Turkey red styles of work, and caused
them to nourish at Elberfeld, and some other places on the continent,
whither a good deal of the English yarns are sent to be dyed, then
brought back, and manufactured into ginghams, checks, &c., or forwarded
directly thence to our Russian customers. This fact places our fiscal
laws in the same odious light as the facility of pirating printer’s
patterns with impunity does our chancery laws.
Before cloth can receive good figured impressions its surface must be
freed from fibrous down by SINGEING, and be rendered smooth by the
CALENDER. See these articles. They are next bleached, with the exception
of those destined for Turkey red. See BLEACHING and MADDER. After they
are bleached, dried, singed, and calendered, they are lapped round in
great lengths of several pieces, stitched endwise together, by means of
an apparatus called, in Manchester, a _candroy_, which bears on its
front edge a rounded iron bar, transversely grooved to the right and
left from the centre, so as to spread out the web as it is drawn over it
by the rotation of the lapping roller. See a figure of this bar
subservient to the cylinder printing-machine.
Four different methods are in use for imprinting figures upon calicoes:
the first is by small wooden blocks, on whose face the design is cut,
which are worked by hand; the second is by larger wood-cut blocks,
placed in either two or three planes, standing at right angles to each
other, called a Perrotine, from the name of its inventor; the third is
by flat copper plates, a method now almost obsolete; and the fourth is
by a system of copper cylinders, mounted in a frame of great elegance,
but no little complexity, by which two, three, four, or even five
colours may be printed on in rapid succession by the mere rotation of
the machine driven by the agency of steam or water. The productive
powers of this printing automaton are very great, amounting for some
styles to a piece in the minute, or a mile of cloth in the hour. The
fifth colour is commonly communicated by means of what is called a
surface cylinder, covered with wooden figures in bas-relief, which, by
rotation, are applied to a plane of cloth imbued with the thickened
mordants.
The hand blocks are made of sycamore or pear-tree wood, or of deal faced
with these woods, and are from two to three inches thick, nine or ten
inches long, and five broad, with a strong box handle on the back for
seizing them by. The face of the block is either carved in relief into
the desired design, like an ordinary wood-cut, or the figure is formed
by the insertion edgewise into the wood of narrow slips of flattened
copper wire. These tiny fillets, being filed level on the one edge, are
cut or bent into the proper shape, and forced into the wood by the taps
of a hammer at the traced lines of the configuration. Their upper
surfaces are now filed flat, and polished into one horizontal plane, for
the sake of equality of impression. As the slips are of equal thickness
in their whole depth, from having been made by running the wire through
between the steel cylinders of a flatting mill, the lines of the figure,
however much they get worn by use, are always equally broad as at first;
an advantage which does not belong to wood-cutting. The interstices
between the ridges thus formed are filled up with felt-stuff. Sometimes
a delicate part of the design is made by the wood-cutter, and the rest
by the insertion of copper slips.
The colouring matter, properly thickened, is spread with a flat brush,
by a child, upon fine woollen cloth, stretched in a frame over the wax
cloth head of a wooden drum or sieve, which floats inverted in a tubful
of old paste, to give it elastic buoyancy. The inverted sieve drum
should fit the paste tub pretty closely. The printer presses the face of
the block on the drum head, so as to take up the requisite quantity of
colour, applies it to the surface of the calico, extended upon a flat
table covered with a blanket, and then strikes the back of the block
with a wooden mallet, in order to transfer the impression fully to the
cloth. This is a delicate operation, requiring equal dexterity and
diligence. To print a piece of cloth 28 yards long, and 30 inches broad,
no less than 672 applications of a block, 9 inches long and 5 inches
broad, are requisite for each colour; so that if there are 3 colours, or
3 hands, as the French term it, no less than 2016 applications will be
necessary. The blocks have pin-points fixed into their corners, by means
of which they are adjusted to their positions upon the cloth, so as to
join the different parts of the design with precision. Each printer has
a colour-tub placed within reach of his right hand; and for every
different colour he must have a separate sieve. Many manufacturers cause
their blocks to be made of three layers of wood, two of them being deal
with the grain crossed to prevent warping, and the third sycamore for
engraving.
[Illustration: 231 232]
The printing shop is an oblong apartment, lighted with numerous windows
at each side, and having a solid table opposite to each window. The
table B, _fig._ 231. is formed of a strong plank of well-seasoned hard
wood, mahogany, or marble, with a surface truly plane. Its length is
about 6 feet, its breadth 2 feet, and its thickness 3, 4, or 5 inches.
It stands on strong feet, with its top about 36 inches above the floor.
At one of its ends there are two brackets C for supporting the axles of
the roller E, which carries the white calico to be printed. The hanging
rollers E are laid across joists fixed near the roof of the apartment
above the printing shop, the ceiling and floor between them being open
bar work, at least in the middle of the room. Their use is to facilitate
the exposure, and, consequently, the drying of the printed pieces, and
to prevent one figure being daubed by another. Should they come to be
all filled, the remainder of the goods must be folded lightly upon the
stool D.
The printer stretches a length of the piece upon his table A B, taking
care to place the selvage towards himself, and one inch from the edge.
He presents the block towards the end, to determine the width of its
impression, and marks this line A B, by means of his square and tracing
point. The spreader now besmears the cloth with the colour, at the
commencement, upon both sides of the sieve head; because, if not
uniformly applied, the block will take it up unequally. The printer
seizes the block in his right hand, and daubs it twice in different
directions upon the sieve cloth, then he transfers it to the calico in
the line A B, as indicated by the four points _a b c d_, corresponding
to the four pins in the corners of the block. Having done so, he takes
another daub of the colour, and makes the points _a b_ fall on _c d_, so
as to have at the second stamp _a´ b´_, covering _a b_ and _c´ d´_; and
so on, through the rest, as denoted by the accented letters. When one
table length is finished, he draws the cloth along, so as to bring a new
length in its place.
The grounding in, or re-entering (_rentrage_), of the other colours is
the next process. The blocks used for this purpose are furnished with
pin-points, so adjusted that, when they are made to coincide with the
pin-points of the former block, the design will be correct; that is to
say, the new colour will be applied in its due place upon the flower or
other figure. The points should not be allowed to touch the white cloth,
but should be made to fall upon the stem of a leaf, or some other dark
spot. These _rentrages_ are of four sorts:--1. One for the mordants, as
above; 2. one for topical colours; 3. one for the application of reds;
and, 4., one for the application of resist pastes or reserves. These
styles have superseded the old practice of pencilling.
The Perrotine is a machine for executing block-printing by mechanical
power; and it performs as much work, it is said, as 20 expert hands. I
have seen its operation, in many factories in France and Belgium, in a
very satisfactory manner; but I have reason to believe that there are
none of them as yet in this country. Three wooden blocks, from 2-1/2 to
3 feet long, according to the breadth of the cloth, and from 2 to 5
inches broad, faced with pear-tree wood, engraved in relief, are mounted
in a powerful cast-iron frame work, with their planes at right angles to
each other, so that each of them may, in succession, be brought to bear
upon the face, top, and back of a square prism of iron covered with
cloth, and fitted to revolve upon an axis between the said blocks. The
calico passes between the prism and the engraved blocks, and receives
successive impressions from them as it is successively drawn through by
a winding cylinder. The blocks are pressed against the calico through
the agency of springs, which imitate the elastic pressure of the
workman’s hand. Each block receives a coat of coloured paste from a
woollen surface, smeared after every contact with a mechanical brush.
One man, with one or two children for superintending the colour-giving
surfaces, can turn off about 30 pieces English per day, in three
colours, which is the work of fully 20 men and 20 children in block
printing by hand. It executes some styles of work to which the cylinder
machine, without the surface roller, is inadequate.
The copper-plate printing of calico is almost exactly the same as that
used for printing engravings on paper from flat plates, and being nearly
superseded by the next machine, need not be described.
[Illustration: 233]
The cylinder printing machine consists, as its name imports, of an
engraved copper cylinder, so mounted as to revolve against another
cylinder lapped in woollen cloth, and imbued with a coloured paste, from
which it derives the means of communicating coloured impressions to
pieces of calico passed over it. _Fig._ 233. will give the reader a
general idea of this elegant and expeditious plan of printing. The
pattern is engraved upon the surface of a hollow cylinder of copper, or
sometimes gun-metal, and the cylinder is forced by pressure upon a
strong iron mandrel, which serves as its turning shaft. To facilitate
the transfer of the impression from the engraving to the cotton cloth,
the latter is lapped round another large cylinder, rendered elastic by
rolls of woollen cloth, and the engraved cylinder presses the calico
against this elastic cushion, and thereby prints it as it revolves. Let
A be the engraved cylinder mounted upon its mandrel, which receives
rotatory motion by wheels on its end, connected with the steam or water
power of the factory. B is a large iron drum or roller, turning in
bearings of the end frames of the machine. Against that drum the
engraved cylinder A is pressed by weights or screws; the weights acting
steadily, by levers, upon its brass bearings. Round the drum B the
endless web of felt or blanket stuff _a a_, travels in the direction of
the arrow, being carried round along with the drum B, which again is
turned by the friction of contact with the cylinder A. _c_ represents a
clothed wooden roller, partly plunged into the thickened colour of the
trough D D. That roller is also made to bear, with a moderate force,
against A, and thus receives, by friction, in some cases, a movement of
rotation. But it is preferable to drive the roller C from the cylinder
A, by means of a system of toothed wheels attached to their ends, so
that the surface speed of the wooden or paste roller shall be somewhat
greater than that of the printing cylinder, whereby the colour will be
rubbed, as it were, into the engraved parts of the latter.
As the cylinder A is pressed upwards against B, it is obvious that the
bearers of the trough and its roller must be attached to the bearings of
the cylinder A, in order to preserve its contact with the colour-roller
C. _b_ is a sharp-edged ruler of gun-metal or steel, called the _colour
doctor_, screwed between two gun-metal stiffening bars; the edge of
which wiper is slightly pressed as a tangent upon the engraved roller A.
This ruler vibrates with a slow motion from side to side, or right to
left, so as to exercise a delicate shaving action upon the engraved
surface, as this revolves in the direction of the arrow. _c_ is another
similar sharp-edged ruler, called the _lint doctor_, whose office it is
to remove any fibres which may have come off the calico in the act of
printing, and which, if left on the engraved cylinder, would be apt to
occupy some of the lines, or at least to prevent the colour from filling
them all. This _lint doctor_ is pressed very slightly upon the cylinder
A, and has no traverse motion.
What was stated with regard to the bearers of the colour trough D,
namely, that they are connected, and moved up and down together with the
bearings of the cylinder A, may also be said of the bearers of the two
doctors.
The working of this beautiful mechanism may now be easily comprehended.
The web of calico, indicated in the figure by the letter _d_, is
introduced or carried in along with the blanket stuff _a a_, in the
direction of the arrow, and is moved onward by the pressure of the
revolving cylinder A, so as to receive the impression of the pattern
engraved on that cylinder.
Before proceeding to describe the more complex calico-machine which
prints upon cloth, 3, 4, or 5 colours at one operation, by the rotation
of so many cylinders, I shall explain the modern methods of engraving
the cylinder, which I am enabled to do by the courtesy of Mr. Locket, of
Manchester, an artist of great ingenuity in this department, who
politely allowed me to inspect the admirable apparatus and arrangements
of his factory.
To engrave a copper cylinder 3 or 4 inches in diameter, and from 30 to
36 inches long with the multitude of minute figures which exist in many
patterns, would be a very laborious and expensive operation. The happy
invention made by Mr. Jacob Perkins, in America, for transferring
engravings from one surface to another by means of steel roller dies,
was with great judgment applied by Mr. Locket to calico-printing, so
long ago as the year 1808, before the first inventor came to Europe with
the plan. The pattern is first drawn upon a scale of about 3 inches
square, so that this size of figure being repeated a definite number of
times, will cover the cylinder. This pattern is next engraved in
intaglio upon a roller of softened steel, about 1 inch in diameter, and
3 inches long, so that it will exactly occupy its surface. The engraver
aids his eye with a lens, when employed at this delicate work. This
roller is hardened by heating it to a cherry-red in an iron case
containing pounded bone-ash, and then plunging it into cold water; its
surface being protected from oxidizement by a chalky paste. This
hardened roller is put into a press of a peculiar construction, where,
by a rotatory pressure, it transfers its design to a similar roller in
the soft state; and as the former was in intaglio, the latter must be in
relievo. This second roller being hardened, and placed in an appropriate
volutory press, is employed to engrave by indentation upon the
full-sized copper cylinder, the whole of its intended pattern. The first
roller engraved by hand is called the _die_; the second, obtained from
it by a process like that of a milling tool, is called the _mill_. By
this indentation and multiplication system, an engraved cylinder may be
had for seven pounds, which engraved by hand would cost fifty or
upwards. The restoration of a worn-out cylinder becomes extremely easy
in this way; the mill being preserved, need merely be properly rolled
over the copper surface again.
At other times, the hard roller _die_ is placed in the upper bed of a
screw press, not unlike that for coining, while the horizontal bed below
is made to move upon strong rollers mounted in a rectangular iron frame.
In the middle of that bed a smooth cake or flat disc of very soft iron,
about 1 inch thick, and 3 or 4 inches in diameter, is made fast by four
horizontal adjusting screws, that work in studs of the bed frame. The
_die_ being now brought down by a powerful screw, worked by toothed
wheel-work, and made to press with force upon the iron cake, the bed is
moved backwards and forwards, causing the roller to revolve on its axles
by friction, and to impart its design to the cake. This iron disc is now
case-hardened by being ignited amidst horn shavings in a box, and then
suddenly quenched in water, when it becomes itself a die in relievo.
This disc die is fixed in the upper part of a screw press with its
engraved face downwards, yet so as to be movable horizontally by
traverse screws. Beneath this inverted bed, sustained at its upper
surface by friction-rollers, a copper cylinder 30 inches long, or
thereby, is mounted horizontally upon a strong iron mandrel, furnished
with toothed wheels at one of its ends, to communicate to it a movement
upon its axis through any aliquot arcs of the circle. The disc die being
now brought down to bear upon the copper cylinder, this is turned round
through an arc corresponding in length to the length of the die; and
thus, by the steady downward pressure of the screw, combined with the
revolution of the cylinder, the transfer of the engraving is made in
intaglio. This is I believe the most convenient process for engraving,
by transfer, the copper of a one-cylinder machine. But when 2, 3, or 4
cylinders are to be engraved with the same pattern for a two, three, or
four-coloured machine, the die and the mill roller plan of transfer is
adopted. In this case, the hardened roller die is mounted in the upper
bed of the transfer press, in such a way as to be capable of rotation
round its axis, and a similar roller of softened steel is similarly
placed in the under bed. The rollers are now made to bear on each other
by the action of the upper screw, and while in hard contact, the lower
one is caused to revolve, which, carrying round the upper by friction,
receives from it the figured impression in relief. When cylinders for a
three-coloured machine are wanted, three such _mills_ are made
fac-similes of each other; and the prominent parts of the figure which
belong to the other two copper cylinders are filed off in each one
respectively. Thus three differently figured _mills_ are very readily
formed, each adapted to engrave its particular figure upon a distinct
copper cylinder.
Some copper cylinders for peculiar styles are not graved by indentation,
as just described, but etched by a diamond point, which is moved by
mechanism in the most curious variety of configurations, while the
cylinder slowly revolves in a horizontal line beneath it. The result is
extremely beautiful, but it would require a very elaborate set of
drawings to represent the machinery by which Mr. Locket produces it. The
copper is covered by a resist varnish while being heated by the
transmission of steam through its axis. After being etched, it is
suspended horizontally by the ends, for about five minutes, in an oblong
trough charged with dilute nitric acid.
With regard to the two and three-coloured machines, we must observe,
that as the calico in passing between the cylinders is stretched
laterally from the central line of the web, the figures engraved upon
the cylinders must be proportionally shortened, in their lateral
dimensions especially, for the first and second cylinder.
Cylinder printing, though a Scotch invention, has received its wonderful
development in England, and does the greatest honour to this country.
The economy of labour introduced by these machines is truly marvellous;
one of them, under the guidance of a man to regulate the rollers, and
the service of a boy, to supply the colour troughs, being capable of
printing as many pieces as nearly 200 men and boys could do with blocks.
The perfection of the engraving is most honourable to our artisans. The
French with all their ingenuity and neat-handedness can produce nothing
approaching in excellence to the engraved cylinders of Manchester,--a
painful admission, universally made to me by every eminent manufacturer
in Alsace, whom I visited in my late tour.
Another modification of cylinder printing, is that with wooden rollers
cut in relief: it is called _surface printing_, probably because the
thickened colour is applied to a tense surface of woollen cloth, from
which the roller takes it up by revolving in contact with the cloth.
When the copper cylinders, and the wooden ones, are combined in one
apparatus, it has got the appropriate name of the _union_ printing
machine.
In mounting three or more cylinders in one frame, many more adjustments
become necessary than those described above. The first and most
important is that which ensures the correspondence between the parts of
the figures in the successive printing rollers, for unless those of the
second and subsequent engraved cylinders be accurately inserted into
their respective places, a confused pattern would be produced upon the
cloth as it advances round the pressure cylinder B, _figs._ 233, 234.
Each cylinder must have a forward adjustment in the direction of
rotation round its axis, so as to bring the patterns into correspondence
with each other in the length of the piece; and also a lateral or
traverse adjustment in the line of its axis, to effect the
correspondence of the figures across the piece; and thus, by both
together, each cylinder may be made to work symmetrically with its
fellows.
[Illustration: 234]
_Fig._ 234. is a cross section of a four-colour cylinder machine, by
which the working parts are clearly illustrated.
A A A is a part of the two strong iron frames or cheeks, in which the
various rollers are mounted. They are bound together by the rods and
bolts _a a a a_.
B is the large iron pressure cylinder, which rests with its gudgeons in
bearings or bushes, which can be shifted up and down in slots of the
side cheeks A A. These bushes are suspended from powerful screws _b_,
which turn in brass nuts, made fast to the top of the frame A, as is
plainly shown in the figure. These screws serve to counteract the strong
pressure applied beneath that cylinder, by the engraved cylinders D E.
C D E F are the four printing cylinders, named in the order of their
operation. They consist of strong tubes of copper or gun-metal, forcibly
thrust by a screw press upon the iron mandrels, round which as shafts
they revolve.
The first and last cylinder C and F are mounted in brass bearings, which
may be shifted in horizontal slots of the frame A. The pressure roller
B, against whose surface they bear with a very little obliquity
downwards, may be nicely adjusted to that pressure by its elevating and
depressing screws. By this means C and F can be adjusted to B with
geometrical precision, and made to press it in truly opposite
directions.
The bearings of the cylinders D and E are lodged also in slots of the
frame A, which point obliquely upwards, towards the centre of B. The
pressure of these two print cylinders C and F is produced by two screws
_c_ and _d_, which work in brass nuts, made fast to the frame, and very
visible in the figure. The frame-work in which these bearings and screws
are placed, has a curvilinear form, in order to permit the cylinders to
be readily removed and replaced; and also to introduce a certain degree
of elasticity. Hence the pressure applied to the cylinders C and F,
partakes of the nature of a spring; a circumstance essential to their
working smoothly, on account of the occasional inequalities in the
thickness of the felt web and the calico.
The pressure upon the other two print cylinders D and E is produced by
weights acting with levers against the bearings. The bearings of D are,
at each of their ends, acted upon by cylindrical rods, which slide in
long tubular bosses of the frame, and press with their nuts _g_ at their
under end upon the small arms of two strong levers G, which lie on each
side of the machine, and whose fulcrum is at _h_ (in the lower corner at
the left hand). The long arms of these levers G, are loaded with weights
H, whereby they are made to press up against the bearings of the roller
D, with any degree of force, by screwing up the nut _g_, and hanging on
the requisite weights.
The manner in which the cylinder E is pressed up against B, is by a
similar construction to that just described. With each of its bearings,
there is connected by the link _k_, a curved lever I, whose fulcrum or
centre of motion is at the bolt _l_. To the outer end of this lever, a
screw, _m_, is attached, which presses downwards upon the link _n_,
connected with the small arm of the strong lever _k_, whose centre of
motion is at _o_. By turning therefore the screw _m_, the weight L, laid
upon the end of the long arm of the lever K (of which there is one upon
each side of the machine), may be made to act or not at pleasure upon
the bearings of the cylinder E.
In tracing the operation of this exquisite printing machine, we shall
begin with the first engraved cylinder C. Its bearings or bushes shift,
as was already stated, in slots of the frame A. Each of them consists of
a round piece of iron, to which the end of the screw _c_ is joined, in
the same way as at _d_, in the opposite side. In each of these iron
bearings, a concave brass is inserted to support the collar of the
shaft, and in a dovetailed slit of this brass, a sliding piece is
fitted, upon which a set or adjusting screw in the iron bearing acts,
and which, being forced against the copper cylinder C, serves to adjust
the line of its axis, and to keep it steady between its bearings, and
true in its rotatory motion. Upon the iron bearing a plate is screwed,
provided with two flanges, which support the colour trough _q_, and the
colour roller M. This trough, as well as the others to be mentioned
presently, is made of sheet copper in the sides and bottom, and fixed
upon a board; but its ends are made of plates of cast copper or
gun-metal to serve as bearings to the colour roller M. The trough and
its roller may be shifted both together into contact with the printing
cylinder C, by means of the screw _r_. Near _s_, seen above the roller,
C, and _t_ below it, are sections of the two doctors, which keep the
engraved cylinders in sound working condition; the former being the
colour doctor, and the latter the lint doctor. Their ends lie in
brasses, which may be adjusted by the screws _u_ and V, working in the
respective brackets, which carry their brasses, and are made fast to the
iron bearings of the cylinder.
The pressure of the colour doctor is produced by two weights _w_ (see
high up on the frame work), which act on a pair of small levers _x_,
(one on each side of the machine,) and thus, by means of the chains,
tend to lift the arms _y_, attached to the end axles of the doctor. The
pressure of the lint doctor upon the cylinder C, is performed by the
screw _z_, pressing upon an arm which projects downwards, and is
attached to the axle of that doctor.
The bearings of the second printing cylinder D, consist at each end of a
mass of iron (removed in the drawing to show the mechanism below it),
which shifts in the slanting slot of the frame A. In each of these
masses there is another piece of iron, which slides in the transverse
direction, and may be shifted by the adjusting screw _a´_ fixed to it,
and working in a nut cast upon the principal bearing above described. To
the inner bearings, which carry the brasses in which the shaft lies, are
screwed the two curved arms _b´ b´_ to which are attached the bearings,
&c., for the colour trough, and the doctors. In these brasses there are
also dovetailed pieces, which slide and are pressed by set screws
furnished with square heads in the iron secondary bearings, which serve,
as before said, to adjust the printing cylinder in the line of its axis,
while other screws adjust the distance of the cloth upon which the
second colour is printed, and the line of contact with the cylinder B.
N, is the colour roller of D, and _d´_ the colour trough, which rests by
its board upon the lever _e´_; whose centres of motion _f´_, are made
fast to the curved arms _b´_, fixed at the bearings of the cylinder,
and whose ends are suspended by screws _g´_; whereby the colour roller
N, may be pressed with greater or less force to the cylinder D. _h´_ and
_i´_ are the two doctors of this cylinder; the former being the colour,
the latter the lint doctor. They rest, as was said of the cylinder C, in
brasses which are adjustable by means of screws, that work in the studs
or brackets by which the brasses are supported. These brackets must of
course be screwed to the secondary bearing-pieces, in order that they
may keep their position, into whatever direction the bearings may be
shifted. _k´_ and _l´_ are these set screws for the colour and lint
doctors. The pressure of the former upon the cylinder D, is produced by
weights _m´_, acting upon levers _n´_, and pressing by rods or links
_o´_, upon arms attached to each end of the axis of the doctor. (See the
left hand side of the figure near the bottom). The lint-doctor _i´_, is
pressed in a similar way at the other side upon the cylinder D, by the
weights acting upon levers _p´_, and by rods _q´_ upon arms fixed at
each end of the axis of the doctor.
The bearings of the third printing cylinder E, are of exactly the same
construction as that above described, and therefore require no
particular detail. The lint doctor _s_, is here pressed upon the
engraved cylinder by screws _t´_, working in the ends of studs or arms
fixed upon each end of the axis of the doctor, and pressing upon flanges
cast upon the brackets in which the brasses of the doctor’s axis lie,
which are made fast to the bearings of the cylinder E.
The bearings of the fourth copper cylinder F, are also constructed in a
similar way. Each consists of a first bearing, to which is joined the
end of the screw _d_, by which it is made to slide in a slot of the
frame. Another bearing, which contains the brass for the shaft of the
cylinder, can be shifted up and down in a transverse direction by a
screw _z´_, of the second bearing, working in a nut cast upon the first
bearing. To this secondary bearing, plates are made fast by the screws
_v´ v´_ to the inside, to carry the studs or brackets of the doctors
_x´_ and _y´_. In the brasses of the cylinder shaft, dovetailed pieces
are made to slide, being pressed by set screws _w´_, against the
engraved cylinder F, similar to what has been described for adjusting
the cylinders to one another. This cylinder has no separate colour
roller, nor trough, properly speaking, but the colour doctor _y´_ is
made concave to serve the purpose of a trough in supplying the engraved
lines of the cylinder with colour. With this view the top plate of the
doctor is curved to contain the coloured paste, and it is shut up at the
ends by pieces of wood made to fit the curvature of the doctor. Its
pressure against the engraved surface is produced by weights _a´´_,
acting at the ends of arms _b´´_, attached to the ends of the axis of
the doctor. The pressure of the lint doctor _x´_ is given by screws
_c´´_, working in arms attached to the ends of the axis of the doctor,
and pressing upon the flanges _d´´_, cast upon the brackets which carry
the brasses for the axis of the doctor. These brasses are themselves
adjustable, like those of all the other cylinders, by set screws in the
brackets, which work in the nuts formed in the brasses.
_e´´ e´´_, is the endless web of felt stuff which goes round the
cylinder B, and constitutes the soft elastic surface upon which the
printing cylinders C, D, E, and F exercise their pressure. This endless
felt is passed over a set of rollers at a certain distance from the
machine, to give opportunity for the drying up of any colouring paste
which it may have imbibed from the calico in the course of the
impressions. In its return to the machine in the direction of the arrow,
it is led over a guide roller _o_, which is thereby made to revolve.
Upon the two ends of this, and outside of the bearings which are fixed
upon the tops of the frame A, are two eccentrics, one of which serves to
give a vibratory traverse movement to the colour doctors _s´_, _h´_, and
_r´_ of the three cylinders, C, D, and E whilst the other causes the
colour doctor _y´_ of the cylinder F, to make lateral vibrations.
[Illustration: 235]
Q is one of a pair of cast-iron brackets, screwed on at the back of the
side-frames or cheeks A A, to carry the roller filled with white calico
R, ready for the printing operations. Upon the end of the shaft whereon
the calico is coiled, a pulley is fixed, over which a rope passes
suspending a weight in order to produce friction, and thereby resistance
to the action which tends to unwind the calico. In winding it upon that
and similar rollers, the calico is smoothed and expanded in breadth by
being passed over one or more grooved rods, or over a wooden bar S,
_fig._ 235. the surface of which is covered with wire, so as to have the
appearance of a united right and left-handed screw. By this device, the
calico, folded or creased at any part, is stretched laterally from the
centre, and made level. It then passes over the guide-roller _o_, where
it comes upon the surface of the felt _e´´ e´´_, and thence proceeds
under its guidance to the series of printing cylinders.
Three and four-colour machines, similar to the above, are now at work in
many establishments in Lancashire, which will turn off a piece of 28
yards per minute, each of the three or four cylinders applying its
peculiar part of the pattern to the cloth as it passes along, by
ceaseless rotation of the unwearied wheels. At this rate, the
astonishing length of one mile of many-coloured web is printed with
elegant flowers and other figures in an hour. When we call to mind how
much knowledge and skill are involved in this process, we may fairly
consider it as the greatest achievement of chemical and mechanical
science.
Before entering upon the different styles of work which constitute
calico printing, I shall treat, in the first place, of what is common to
them all, namely, the thickening of the mordants and colours. This is an
operation of the greatest importance towards the successful practice of
the art. Several circumstances may require the consistence of the
thickening to be varied; such as the nature of the mordant, its density,
and its acidity. A strong acid mordant cannot be easily thickened with
starch; but it may be by roasted starch, vulgarly called British gum,
and by gum arabic or senegal. Some mordants which seem sufficiently
inspissated with starch, liquefy in the course of a few days; and being
apt to run in the printing-on make blotted work. In France, this evil is
readily obviated, by adding one ounce of spirits of wine to half a
gallon of colour; a remedy which the English excise duties render too
costly.
The very same mordant, when inspissated to different degrees, produces
different tints in the dye-copper; a difference due to the increased
bulk from the thickening substance; thus, the same mordant, thickened
with starch, furnishes a darker shade than when thickened with gum. Yet
there are circumstances in which the latter is preferred, because it
communicates more transparency to the dyes, and because, in spite of the
washing, more or less of the starch always sticks to the mordant. The
gum has the inconvenience, however, of drying too speedily, and of also
increasing too much the volume of the mordants; by both of which causes
it obstructs their combination with the stuff, and the tints become thin
or scratchy.