Chapter V: OF RIPENING DIFFERENT KINDS OF BEER.--The varieties of beer depend (10)

Having explained the peculiar forms of his improved metallic shanks for buttons, and the tools employed in making the same, he proceeds to describe the machinery or apparatus by which he intends to carry his invention into effect. He proposes to take a sheet of metal, say about 30 or 40 feet long, and of the proper width and thickness; which thin sheet is to be wound upon a roller, and placed above the machine, so that it can be easily drawn down into the machine as required for feeding the punches and dies. _Fig._ 210. is a plan view of a machine, intended to work any convenient number of sets of punches and dies placed in rows. Eleven sets of punches and dies are represented, each set being constructed as described under _figs._ 197 to 204; _fig._ 211. is a side view, and _fig._ 212. a longitudinal section, taken through the machine; _figs._ 213. and 214. are transverse sections taken through the machine between the punches and counter dies, _fig._ 213. representing its appearance at the face of the punches, and _fig._ 214. the opposite view of the counter dies. _a a_, are the punches; _b b_, the counter dies; each being mounted in rows in the steel plates _c c_, fixed upon two strong bars _d_ and _e_, by countersunk screws and nuts, the punches and dies being retained in their proper position by the plates, which are screwed on to the front of the steel plates, and press against the collars of the punches and dies. The bars _d_ and _e_ are both mounted on the guide-pins _g g_, fixed in the heads _h h_ of the frame, which guide pins pass through the bosses on the ends of the bars. The bar _d_ is stationary upon the guide pins, being fixed to the heads _h h_, by nuts and screws passed through ears cast on their bosses. The bar _e_ slides freely upon the guide pins _g g_, as it is moved backwards and forwards by the crank _i i_, and connecting-rods _j j_, as the crank shaft revolves. The sheet of thin iron to be operated upon is placed, as before stated, above the machine; its end being brought down as at _a a_, and passed between the guide rod and clearing-plate _k_, and between the pair of feeding-rollers _l l_, which, by revolving, draw down a further portion of the sheet of metal between the punches and dies, after each operation of the punches.

As the counter dies advance towards the punches, they first come in contact with the sheet of metal to be operated upon; and after having produced the pressure which cuts out the discs, the perforations of the sheet are pushed on to the ends of the punches by the counter dies; and in order that the sheet may be allowed to advance, the carriage which supports the axles of the feeding-rollers, with the guide rod and clearing-plate, are made to slide by means of the pin _m_, which works in a slot in the sliding-piece _n_, bearing the axis of the feeding-roller _l l_, the slide _n_, being kept in its place on the frame work by dovetailed guides shown in _fig._ 214.

When the counter dies have advanced near to the sheet of metal, the pin _m_ comes in contact with that end of the slot in the piece _n_, which is next to the punches, and forces the carriage with feed-rollers and clearing-plate, and also the sheet of metal, onwards, as the dies are advanced by the reaction of the cranks; and after they have cut out the discs, and raised the shanks, the sheet of metal will remain upon the punches; and when the bar _e_ returns, the finished backs and shanks are forced out of the counter dies, by the clearing-pins and rods _o o_, which project through the bar _e_, and through the holes before mentioned in the counter dies; these clearing-pins being stationary between the bars _p p_, mounted upon the standard _q q_, on the cross bar of the frame, as shown in _figs._ 210., 212., 213. Immediately after this is done, the pins _m_ come in contact with the other ends of the slots in the pieces _n_, and draw back the feeding-rollers _l l_, together with the clearing-plate _k_, and the sheet of metal, away from the punches into the position represented in the figures.

At this time the feeding of the metal into the machine is effected by a crank-pin _r_, on the end of the crank-shafts coming in contact with the bent end of the sliding-bar _s_, supported in standards _t t_; and as the crank-shaft revolves, this pin _r_ forces the bar _s_ forward, and causes the tooth or pall _u_, on its reverse end, to drive the racket-wheel _v_, one or more teeth; and as the racket-wheel _v_ is fixed on to the end of the axle of one of the rollers _l_, it will cause that roller to revolve; and by means of the pair of spur-pinions on the other ends of the axles of the feeding-rollers, they will both revolve simultaneously, and thereby draw down the sheet of metal into the machine. It will be perceived that the standards which support the clearing-plate and guide-bar are carried by the axles of the feeding rollers, and partake of their sliding motion: also that the clearing-pins _o_, are made adjustable between the bars _p_, to correspond with the counter dies. There is an adjustable sliding stop _x_ upon the bar _s_, which comes in contact with the back standard _t_, and prevents the bar _s_ sliding back too far, and consequently regulates the quantity of sheet metal to be fed into the machine by the pall and ratchet-wheel, in order to suit different sizes of punches and dies. In case the weight of the bar _c_, carrying the counter dies, should wear upon its bearings, the guide pins _g g_, have small friction-rollers _y y_, shown under the bosses of this bar, which friction-rollers run upon adjustable beds or planes _z z_, by which means the guide pins may be partially relieved from the weight of the bar _c_, and the friction consequently diminished.

C.

CABLE. (_Cable_, Fr.; _Ankertau_, Germ.) A strong rope or chain, connecting the ship with the anchor for the purpose of mooring it to the ground. The _sheet anchor_ cable is the strongest, and is used at sea; the _stream_ cable is more slender, being used chiefly in rivers. A cable’s length is 120 fathoms. The greatest improvement in mooring vessels has been the introduction of the chain cable, which, when duly let out, affords in the weight of its long catenary curve, an elastic tension and play to the ship under the pressure of wind. The dead strain upon the anchor is thus greatly reduced, and the sudden pull by which the flukes or arms are readily snapped is in a great measure obviated. The best iron cables are chains made of links, bound and braced by rods across their middle. Experience has taught that the ends of these links wear out much sooner than the sides. To remedy this evil, Mr. Hawkes, iron manufacturer, obtained a patent in July, 1828, for constructing these anchor chains with links considerably stouter at the ends than in the middle. With this view, he forms the short rods of iron, of which the links are to be made, with swells or protuberances about one third of their length from each of their ends, so that when these are welded together, the slenderer parts are at the sides, and the thicker at the ends of the elliptic links. Such rods as the above are formed at once by rolling, swagging, or any other means. When the link is welded, it may be strengthened, by a brace or stretcher fixed across the middle.

The first avowed proposal to substitute iron cables for cordage in the sea service, was made by Mr. Slater, surgeon of the navy, who obtained a patent for the plan in 1808, though he does not seem to have had the means of carrying it into effect; a very general misfortune with ingenious projectors. It was Captain Brown of the West India merchant service who, in 1811, first employed chain cables in the vessel Penelope, of 400 tons burden, of which he was captain. He made a voyage in this ship from England to Martinique and Guadaloupe and home again, in the course of four months, having anchored many times in every variety of ground without any accident. He multiplied his trials, and acquired certain proofs that iron might be substituted for hemp in making cables, not only for mooring vessels, but for the standing rigging. Since this period chain cables have been universally introduced into all the ships of the royal navy, but the twisted links employed at first by Brown, have been replaced by straight ones, stayed in the middle with a cross rod, the contrivance of Mr. Brunton, which was secured by patent in this country and in France; but the latter patent was suffered to fall from not being acted upon within the two years specified by law.

The first thing to be considered in the manufacture of iron cables is, to procure a material of the best quality, and, in using it, always to keep in view the direction of the strain, in order to oppose the maximum strength of the iron to it. The best form of the links may be deduced from the following investigation.

Let A B _fig._ 215. be a circular link or ring, of one inch rod iron, the outer circumference of the ring being 15 inches, and the inner 9. If equal opposite forces be applied to the two points of the link C D, pulling C towards E, and D towards F, the result will be, when the forces are sufficiently intense, that the circular form of the link will be changed into another form with two round ends and two parallel sides, as seen in _fig._ 216. The ratio of the exterior to the interior periphery which was originally as 15 to 9, or 5 to 3, is no longer the same in _fig._ 216. Hence there will be a derangement in the relative position of the component particles, and consequently their cohesion will be progressively impaired, and eventually destroyed. In _fig._ 215. the segment M N of the outside periphery being equal to 3 inches, the corresponding inside segment will be 3/5 of it, or 1-4/5 inches. If this portion of the link, in consequence of the stretching force, comes to be extended into a straight line, as shown in _fig._ 216., the corresponding segments, interior and exterior, must both be reduced to an equal length. The matter contained in the 3 inches of the outside periphery must therefore be either compressed, that is, condensed into 1-4/5 inch, or the inside periphery, which is only 1-4/5 inch already, must be extended to 3 inches; that is to say, the exterior condensation and the interior expansion must take place in a reciprocal proportion. But, in every case, it is impossible to effect this contraction of one side of the rod, and extension of the other, without disrupture of the link.

Let us imagine the outside periphery divided into an infinity of points, upon each of which equal opposite forces act to straighten the curvature: they must undoubtedly occasion the rupture of the corresponding part of the internal periphery. This is not the sole injury which must result; others will occur, as we shall perceive in considering what passes in the portion of the link which surrounds C D, _fig._ 216., whose length is 4-1/2 inches outside, and 2-1/10 inside. The segments M P and N O, _fig._ 215., are actually reduced to semi-circumferences, which are inside no more than half an inch, and outside as before. There is thus contraction in the interior, with a quicker curvature or one of shorter radius in the exterior. The derangement of the particles takes place here, in an order inverse to that of the preceding case, but it no less tends to diminish the strength of that portion of the link; whence we may certainly conclude that the circular form of cable links is an extremely faulty one.

Leaving matters as we have supposed in _fig._ 215., but suppose that G is a rod introduced into the mail, hindering its two opposite points A B from approximating. This circumstance makes a remarkable change in the results. The link pulled as above described, must assume the quadrilateral form shown in _fig._ 217. It offers more resistance to deformation than before; but as it may still suffer change of shape, it will lose strength in so doing, and cannot therefore be recommended for the construction of cables which are to be exposed to very severe strains.

Supposing still the link to be circular, if the ends of the stay comprehended a larger portion of the internal periphery, so as to leave merely the space necessary for the plan of the next link, there can be no doubt of its opposing more effectively the change of form, and thus rendering the chain stronger. But, notwithstanding, the circular portions which remain between the points of application of the strain and the stay, would tend always to be straightened, and of consequence to be destroyed. Besides, though we could construct circular links of sufficient strength to bear all strains, we ought still to reject them, because they would consume more materials than links of a more suitable form, as we shall presently see.

The effect of two opposite forces applied to the links of a chain, is, as we have seen, to reduce to a straight line or a straight plane every curved part which is not stayed; whence it is obvious that twisted links, such as Brown first employed, even with a stay in their middle, must of necessity be straightened out, because there is no resistance in the direction opposed to the twist. A cable formed of twisted links, for a vessel of 400 tons stretches 30 feet, when put to the trial strain, and draws back only 10 feet. This elongation of 20 feet proceeds evidently from the straightening of the twist in each link, which can take place only by impairing the strength of the cable.

From the preceding remarks, it appears that the strongest links are such as present, in their original form, straight portions between the points of tension; whence it is clear that links with parallel sides and round ends, would be preferable to all others, did not a good cable require to be able to resist a lateral force, as well as one in the direction of its length.

Let us suppose that by some accident the link _fig._ 216. should have its two extremities pulled towards Y and Z, whilst an obstacle X, placed right opposite to its middle, resisted the effort. The side of the link which touches X, would be bent inwards; but if as in _fig._ 218., there is a stay A G B, the two sides would be bent at the same time; the link would notwithstanding assume a faulty shape.

In thus rejecting all the vicious forms, we are naturally directed to that which deserves the preference. It is shown in _fig._ 219. This link has a cast-iron stay with large ends, it presents in all directions a great resistance to every change of form; for let it be pulled in the direction _a b_, against an obstacle _c_, it is evident that the portions _d e_ and _d f_, which are supported by the parts _g e_ and _g f_, cannot get deformed or be broken without the whole link giving way. As the matter composing _g e_ and _g f_ cannot be shortened, or that which composes _d e_ and _d f_ be lengthened, these four sides will remain necessarily in their relative positions, by virtue of the large-ended stay _h_, whose profile is shown in _fig._ 220.

We have examined the strength of a link in every direction, except that perpendicular to its plane. _Fig._ 221. represents the assemblage of three links in the above predicament; but we ought to observe, that the obstacle C, placed between the links A B, must be necessarily very small, and could not therefore resist the pressure or impact of the two lateral links.

_Process of manufacturing iron cables._--The implements and operations are arranged in the following order:--

1. A reverberatory furnace (see IRON), in which a number of rods or round bars of the best possible wrought-iron, and of proper dimensions, are heated to bright ignition.

2. The cutting by a machine of these bars, in equal lengths, but with opposite bevels, to allow of the requisite crossing and splicing of the ends in the act of welding.

3. The bending of each of these pieces by a machine, so as to form the links; the last two operations are done rapidly while the iron is red-hot.

4. The welding of the links at small forge fires, fitted with tools for this express purpose, and the immediate introduction of the stay, by means of a compound lever press.

5. Proving the strength of the cables by an hydraulic press, worked by two men turning a winch furnished with a fly wheel.

The furnace is like those used in the sheet-iron works, but somewhat larger, and needs no particular description here.

_Figs._ 222. and 223. are a plan and elevation of the shears with which the rods are cut into equal pieces, for forming each a link. It is moved at Mr. Brunton’s factory by a small steam engine, but, for the sake of simplicity, it is here represented worked by four or more labourers, as it may be in any establishment. These must be relieved however frequently by others, for I believe each shears’ machine is calculated to require nearly one horse in steam power. It is portable and must be placed in the neighbourhood of both the furnace and bending machine.

A and B are the two cast-iron limbs of the shears. The first is fixed and the second is movable by means of a crank shaft C, driven by a heavy fly-wheel weighing 7 or 8 cwt.

The cutting jaws G are mounted with pieces of steel which are made fast by bolts, and may be changed at pleasure.

E, the bar of iron to be cut. It is subjected, immediately upon being taken out of the fire, to the shears, under a determinate uniform angle, care being taken not to let it turn round upon its axis, lest the planes of the successive incisions should become unequal.

F is a stop which serves to determine, for the same kind of chain, the equality of length in the link pieces.

_Figs._ 224, 225, 226. plan and elevations of the machine for bending the links into an elliptic form. It is represented at the moment when a link is getting bent upon it.

A is an elliptic mandrel of cast-iron; it is fixed upon the top of a wooden pillar B, solidly supported in the ground. C is the jaw of the vice, pressed by a square-headed screw against the mandrel A.

D part of the mandrel comprehended between X and Y, formed as an inclined plane, so as to preserve an interval equal to the diameter of the rod between the two surfaces that are to be welded together.

E rectangular slots (shears) passing through the centre of the nut of the mandrel, in which each of the pins F may be freely slidden.

G horizontal lever of wrought-iron six feet long. It carries at H a pulley or friction-roller of steel, whose position may be altered according to the diameter of the links. It is obvious that as many mandrels are required as there are sizes and shapes of links.

The piece of iron intended to form a link being cut, is carried, while red-hot, to the bending machine, where it is seized with the jaw of the vice C, by one of its ends, the slant of the cut being turned upwards; this piece of iron has now the horizontal direction _m n_; on pushing the lever G in the line of the arrow, the roller H will force _m n_ to be applied successively in the elliptic groove of the mandrel; thus finally the two faces that are to be welded together will be placed right opposite each other.

The length of the small diameter of the ellipse ought to exceed by a little the length of the stay-piece, to allow of this being readily introduced. The difference between the points F, E is equal to the difference of the _radii vectores_ of the ellipse. Hence it will be always easy to find the eccentricity of the ellipse.

_Fig._ 227. is a lever press for squeezing the links upon their stays, after the links are welded. This machine consists of a strong cast-iron piece A, in the form of a square, of which one of the branches is laid horizontally, and fixed to a solid bed by means of bolts; the other branch, composed of two cheeks, leaving between them a space of two inches, stands upright. These two cheeks are united at top, and on the back of their plane by a cross piece B. C, a rectangular staple, placed to the right and left of the cheeks through which is passed the mandrel D, which represents and keeps the place of the following link. E, is a press lever, 6 feet long. F, clamp and counterclamp, between which the link is pressed at the moment when the stay is properly placed. There are other clamps, as well as staples C, for changing with each changed dimension of links.

The links bent, as we have seen, are carried to the forge hearth to be welded, and to receive their stay; two operations performed at one heating. Whenever the welding is finished, while the iron is still red-hot, the link is placed upright between the clamps F; then a workman introduces into the staple the mandrel D, and now applies the stay with a pair of tongs or pincers, while another workman strikes down the lever E forcibly upon it. This mechanical compression first of all joins perfectly the sides of the link against the concave ends of the stay, and afterwards the retraction of the iron on cooling increases still more this compression.

If each link be made with the same care, the cable must be sound throughout. It is not delivered for use however till it be proved by the hydraulic press, at a draw-bench made on purpose. The press is an horizontal one, having the axis of its ram in the middle line of the draw-bench, which is about 60 feet long, and is secured to the body of the press by strong bolts.

The portion of chain under trial, being attached at the one end to the end of the ram of the press, and at the other to a cross-bar at the extremity of the draw-bench, two men put the press in action, by turning the winch which works by a triple crank three forcing pumps alternately; the action being equalized by means of a heavy fly-wheel. As long as the resistance does not exceed the force of two men, the whole three pumps are kept in play. After a while one pump is thrown out of geer and next another, only one being worked towards the conclusion. The velocity of the ram being retarded first one third and next two thirds, gives the men a proportional increase of mechanical power.

The strength of two average men thus applied being computed, enables us to know at every instant the resistance opposed by the chain to the pressure of the ram. The strain usually applied to the stronger cables is about 500 tons.

The side beams of the draw-bench are of cast-iron, 6 inches in diameter; the different pieces composing it are adjusted to each other end-wise by turned joints. Props also of cast-iron support the beams two feet asunder, and at the height of 30 inches above the ground. The space between them is filled with an oak plank on which the trial chain is laid.

Strength of iron-cables compared to hemp cables:--

+---------------------+----------------------+-----------+
| 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.

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.