Popular Technology Volume I Part 11

THE TRUNK-MAKER.

1. The manufacture of trunks is equally simple with that of making harness. In common cases, it consists chiefly in lining the inside of a wooden box with paper, or some kind of cloth, and covering the outside with a skin, or with leather, which is fastened to the wood by means of tacks. Narrow strips of leather are fastened upon hair trunks with bra.s.s nails, by way of ornament, as well as to confine the work.

2. Instead of a wooden box, oblong rims of iron, and very thick, solid pasteboard, fastened together by means of strong thread, are used in the best kinds of trunks. The frame or body, thus formed, is covered with some substantial leather, which is first stuck on with paste, and then secured by sewing it to the pasteboard with a waxed thread. Over the whole, are applied strips of iron, fastened with bra.s.s or copper nails with large heads. The lines and figures on the leather, added by way of ornament, are produced by a _crease_, a tool made of wood, ivory, or whalebone. Its form is much like that of the blade of a common paper-folder.

3. How long trunk-making has been a separate trade, cannot be exactly ascertained. The trunk-makers in France were incorporated into a company, in 1596. In the United States, this branch of business is very commonly united with that of the saddler and harness-maker.

[Ill.u.s.tration: SOAP & CANDLE MAKER.]

THE SOAP-BOILER, AND THE CANDLE-MAKER.

THE SOAP-BOILER.

1. The business of the soap-boiler consists in manufacturing soap, by the combination of certain oily and alkaline substances.

2. The earliest notice of this useful article occurs in the works of Pliny, in which it is stated, that soap was composed of tallow and ashes; that the mode of combining them was discovered by the Gauls; but that the German soap was the best.

3. For many ages before the invention of soap, saponaceous plants, and several kinds of earth, together with animal matters and the ley from ashes, were employed for the purpose of cleansing the skin, and articles of clothing. The idea of combining some of these substances, with the view of forming soap, probably originated in accident.

4. The vegetable oils and animal fats, capable of saponification, are very numerous; but those most commonly employed in the manufacture of the soaps of commerce, are olive-oil, whale-oil, tallow, lard, palm-oil, and rosin; and the alkalies with which these are most frequently combined, are soda, the ley of ashes, or its residuum, potash.

5. Soda is sometimes called the _mineral alkali_; because it is found, in some parts of the world, in the earth. It was known to the ancients, at a very early period, under the denomination of _natron_.

It received this appellation from the lakes of Natron, in Egypt, from the waters of which it was produced by evaporation, during the summer season.

6. The soda of commerce is now chiefly obtained from the _salsola_, a genus of plants which grows on the sea-sh.o.r.e. In Spain, the plant from which soda is obtained is denominated _barilla_; hence, the substance produced from it by incineration has received the same appellation.

The ashes of a sea-weed which grows on the coasts of Scotland and Ireland, is called _kelp_. In Europe, barilla and kelp are more extensively employed in the manufacture of soap than any other alkaline substances; but, in this country, where wood is so much used for fuel, common ashes are generally preferred.

7. The process of making the ordinary brown or yellow soap, from wood-ashes, is conducted in the following manner. The alkali is first obtained in a state of solution in water, by _leeching_ the ashes as described in page 26, and then poured, in a weak state, into a copper or iron caldron, having a large wooden tub carefully affixed to the top of it.

8. When the ley has been properly heated, the tallow, either in a _tried_ state or in the suet, is gradually added. More ley, of greater concentration, is poured in; and the ingredients are moderately boiled for several hours; while a person, as represented in the preceding cut, aids their chemical union by agitating them with a wooden spatula.

9. After a quant.i.ty of rosin has been added, and properly incorporated with the other materials, the fire is withdrawn until the next morning, when it is again raised; then, with the view of forming the _paste_ into hard soap, a quant.i.ty of muriate of soda (common salt) is added. The muriatic acid of this substance, uniting with the potash, forms with it muriate of potash, which dissolves in the water, while the soda combines with the tallow and rosin. Hard soap, therefore, contains no potash; although this alkali is generally employed during the early part of the process of making it.

10. After the addition of the muriate of soda, the boiling and stirring are continued two or three hours, when the fire is withdrawn, and the contents of the caldron are suffered to be at rest. When the soap has completely separated from the watery part and extraneous matters, it is laded into another caldron, again diluted with strong ley, and heated. The _paste_ having been brought to a proper consistence, more common salt is added as before, and for the same purposes.

11. The chemical part of the process having been thus completed, the soap is laded into single wooden boxes, or into one or more composed of several distinct frames, which can be removed separately from the soap, after it has become solid enough to stand without such support.

The soap is cut into bars, of nearly a uniform size, by means of a small bra.s.s wire.

12. Manufacturers of soap have contrived various methods of adulterating this article, or of adding ingredients which increase its weight, without adding to its value. The most common means employed for this purpose is water, which may be added, in some cases, in considerable quant.i.ties, without greatly diminishing the consistence of the soap.

13. This fraud may be detected by letting the soap lie for some time exposed to the atmosphere. The water will thus be evaporated, and its quant.i.ty can be known by weighing the soap, after its loss of the superfluous liquid. To prevent evaporation, while the soap remains on hand, it is said, that some dealers keep it in saturated solutions of common salt. Another method of adulteration is found in the use of pulverized lime, gypsum, or pipe-clay. These substances, however, can be easily detected by means of a solution in alcohol, which precipitates them.

14. The process of manufacturing soft soap, differs but little in its details from that described in the preceding paragraphs. The chief difference consists in omitting the use of salt. Soft soap, therefore, is composed of a greater proportion of water, and more alkali than is necessary to saturate the unctuous matters. Soft soap is made by almost every family in the country, from ashes, grease, and oily matters, reserved for the purpose.

15. The celebrated Ma.r.s.eilles white soap, is composed of

Soda, 6.

Olive-oil, 60.

Water, 34.

Castile soap, of

Soda, 9.

Olive-oil, 76.5.

Water, with a little coloring matter, 14.5.

Fine toilet-soaps are made with oil of almonds, nut-oil, palm-oil, suet, or b.u.t.ter, combined with soda or potash, according to their preparation in a solid or pasty state.

16. In the manufacture of white soap, the tallow is more carefully purified, and no rosin is used. In other particulars, the process differs but little from that employed in the production of the common kind. Two tons of tallow should yield three tons of white soap. In making the same quant.i.ty of common brown or yellow soap, twelve hundred weight less is required, on account of the subst.i.tution of that amount of yellow rosin.

17. The mottled appearance of some soaps is caused by dispersing the ley through it, towards the close of the operation, or by adding a quant.i.ty of sulphate of iron, indigo, or the oxide of manganese.

Castile soap, now manufactured in the greatest perfection at Ma.r.s.eilles, in France, receives its beautifully marbled appearance from the sulphate of iron.

THE CANDLE-MAKER.

1. The subject of the candle-maker's labors may be defined to be a wick, covered with tallow, wax, or spermaceti, in a cylindrical form, which serves, when lighted, for the illumination of objects in the absence of the sun. The business of candle-making is divided into two branches; the one is confined to the manufacturing of tallow candles, and the other, to making those composed of wax or spermaceti.

2. The process of making candles from tallow, as conducted by the tallow-chandler, needs only a brief description, since it differs but little from the method pursued by families in the country, with which most persons are familiar. The difference lies chiefly in the employment of a few conveniences, by which the candles are more rapidly multiplied.

3. The first part of the process consists in preparing a wick, to serve as a foundation. The coa.r.s.e and slightly twisted yarn used for this purpose, is spun in the cotton-factories; and, being wound into b.a.l.l.s, is, in that form, sold to the tallow-chandlers, as well as to individuals who make candles for their own consumption.

4. A sufficient number of threads is combined, to form a wick of a proper size; and, as they are wound from the b.a.l.l.s, they are measured off, and cut to the proper length, by a simple contrivance, which consists of a narrow board, a wooden pin, and the blade of a razor.

The pin and razor are placed perpendicular to the board, at a distance determined by the length of the proposed wick. The wicks are next put upon cylindrical rods, about three feet long; and a great number of these are arranged on a long frame.

5. To obtain the tallow in a proper state for use, it is separated from the membranous part of the suet, by boiling the latter in an iron or copper kettle, and then subjecting the _cracklings_ to the action of a press. The substance that remains, after the tallow has been expressed, is called _greaves_, which are sometimes applied to fattening ducks for market. This is especially the case in the city of London.

6. The _tried_ tallow is prepared for application to the wicks, by heating it to a proper temperature. It is then poured into a suitable receptacle, where it is kept in _order_ either by a moderate fire underneath, or by the occasional addition of hot tallow.

7. The _broaches_, as the sticks with their wicks are called, are taken up, several at a time, either between the fingers or by means of a simple instrument denominated a _rake_, and dipped into the tallow.

They are then returned to the frame, and suffered to cool, while successive broaches are treated in the same way. The dipping is repeated, until the candles have been thickened to the proper size.

8. In the preceding plate, is represented a workman in the act of dipping several broaches of candles, suspended on a rake, which he holds in his hands. The mode of making dipped candles just described, is more generally practised than any other, and in this manner five or six hundred pounds can be made by one hand, in a single day. In some establishments, however, a more complicated apparatus is used, by which every part of the process is greatly expedited.

9. Mould candles are made very differently. The moulds consist of a frame of wood, in which are arranged several hollow cylinders, generally made of pewter. At the lower extremity of each cylinder, is a small hole, for the pa.s.sage of the wick, which is introduced by means of a hook on the end of a wire. The cotton is fastened at the other end, and placed in a perpendicular situation in the centre of the shafts, by means of a wire, which pa.s.ses through the loops of the wicks. The melted tallow, having been poured on the top of the wooden frame, descends into each mould. After the candles have become sufficiently cold, they are extracted from the cylinders with a bodkin, which is inserted into the loop of the wick. One person can thus mould two or three hundred pounds in a day.

10. Candles are also made of bees-wax and spermaceti; but the mode of their manufacture differs in no particular from that of common mould candles. The wicks for wax-candles are usually made of a peculiar kind of cotton, which grows in Asiatic Turkey.

11. Before the wax is applied to this purpose, the coloring matter is discharged. This is effected by bleaching the wax, in the following manner. It is first divided into flakes, or thin laminae, by pouring it, in a melted state, through a colander upon a cylindrical wheel, which, at the same time, is kept revolving, while partly immersed in cold water. The wax, having been removed from the water, is placed upon a table or floor covered with some kind of cloth. Here it is occasionally sprinkled with water, until the bleaching has been completed. The process occupies several weeks, or even months, according to the state of the weather, that being best which is most favorable to a rapid evaporation.

12. Spermaceti is a substance separated from sperm oil, which is obtained from a species of whale, called _physeter macrocephalus_, or _spermaceti cachalot_. This oil is obtained from both the head and body of the animal, but that procured from the former contains twice the quant.i.ty of spermaceti.

13. To separate the spermaceti from the oil yielded by the body, it is first heated, then put into casks, and suffered to stand two or three weeks, in order to _granulate_. The oily part is now filtrated through strainers; and the remainder, which is called _foots_, is again heated, and put into casks. After having stood several weeks, these are put into bags, and submitted to the action of a powerful press.