tion. PREPARING THE TURNERY-WOODS. 25 It is therefore desirable to prepare them for the transition from the yard or cellar to the turning room, by removing the parts which are necessarily wasted, the more intimately to expose them to the air before removal, and they should be always kept away from the fire, or at first in a room altogether without one. It is usual to begin by cutting the logs into pieces of eight or ten inches, or other lengths suited to the general size of the work; and if possible to prepare each piece into a round block, or into two or three, when the wood is irregular, hollow, or cracked. In the latter case, a thin wedge is inserted into the principal crack, and driven down with a wooden maul; or a cleaver such Fig. 7. as fig. 7, which has a sharp edge, and a poll to receive the blow, is used in the same manner; these tools, or the hatchet, are likewise used in splitting up the English woods, when they are beyond the diameters required. The cleft pieces are next roughly trimmed with the hatchet, or else with the paring-knife, a tool of safer and more economical application in the hands of the amateur: it is a lever knife, (the half of a pair of shears,) from two and a half, to three feet long; the cutting edge is near the end which terminates in a hook, the other extremity has a transverse handle; an eye-bolt is screwed into the bench or block for the hook, and a detached cutting board is fixed under the blade, to serve as the support for the wood, and for the knife to cut upon. To avoid waste of material, it is advisable to score with the compasses, upon each end of the rough block, as large a circle as it will allow, to serve as a guide for the knife, until the eye is well accustomed to the work. The block, represented in fig. 8, is adapted to the bearers of the lathe, but any other support will serve equally well. The paring-knife is also employed for other purposes besides those of the turner: it is sometimes made with a curved edge like a * Sometimes the glazier's chipping-knife is used for small pieces of wood instead of the cleaver represented. 26 PREPARING THE TURNERY-WOODS. gouge, and is used in many shaping operations in wood, as in the manufacture of shoe-lasts, clogs, pattens, toys, &c. &c.* Fig. 8. In the absence of the paring-knife or hatchet, the work is fixed in the vice, and rounded with a coarse rasp, but this is much less expeditious by some manufacturers the preparation both of the foreign and English woods is prosecuted still further, by cutting the material into smaller pieces, rough turned and hollowed in the lathe, to the form of boxes, or other articles for which they are specifically intended, and in fact every measure that tends to make the change of circumstances gradual, assists also in the economy, perfection, and permanence of the work. Many of the timber woods are divided at the saw-pit into planks or boards, at an early stage, in order to multiply the surfaces upon which the air may act, and also to leave a less distance for its penetration: after sawing, they should never be allowed to rest in contact, as the partial admission of the air often causes stains or doating: but they are placed either perpendicularly or * A paring-knife similar to the above, but working in a guide, and with an edge 12 or 14 inches long, is a most effective instrument in the hands of the toy-makers. The pieces of birch, alder, &c. are boiled in a cauldron for an hour to soften them, and whilst hot they may be worked with great expedition and perfection. The workmen pare off slices, the plankway of the grain, as large as 4 by 6 inches, almost as quickly as they can be counted: they are wedged tight in rows, like books, to cause them to dry flat and straight, and they seldom require any subsequent smoothing. In making the little wheels for carts, &c., say of one or two inches diameter, and one-quarter or three-eighths of an inch thick, they cut them the crossway of the grain, out of cylinders previously turned and bored; the flexibility of the hot moist wood being such, that it yields to the edge of the knife without breaking transversely as might be expected. PREPARING THE TIMBER-WOODS. 27 horizontally in racks, or they are more commonly stacked in horizontal piles, with parallel slips of wood placed between at distances from about three to six or eight feet, according to the quantity of support required; the pile forms a press to keep the whole flat and straight. Thin pieces will be sufficiently seasoned in about one year's time, but thick wood requires two or three, before it is thoroughly fit to be removed to the warmer temperature of the house for the completion of the drying. Mahogany, cedar, rosewood, and the other large foreign woods, require to be carefully dried after they are cut into plank, as notwithstanding the length of time that sometimes intervenes between their being felled and brought into use, they still retain much of their moisture whilst they remain in the log*. In some manufactories the wood is placed for a few days before it is worked up, in a drying room heated by means of stoves, steam, or hot water, to several degrees beyond the temperature to which the finished work is likely to be subjected. Such rooms are frequently made as air-tight as possible, which appears to be a mistake, as the wood is then surrounded by a warm but stagnant atmosphere, which retains whatever moisture it may have evaporated from the wood. Of late a plan has been more successfully practised in seasoning timber for building purposes, by the employment of heated rooms with a free circulation of air, which enters at the lower part in a hot and dry state, and escapes at the upper charged with the moisture which it freely absorbs in the heated state. The continual ingress of hot dry air, greedy of moisture, so far expedites the drying, that it is accomplished in one-third of the time that is required in the ordinary way in the open air†. * Scientifically considered, the drying is only said to be complete when the wood ceases to lose weight from evaporation; this only occurs after twice or thrice the period usually allowed for the process of seasoning. In many modern buildings small openings are left through the walls to the external air to allow a partial circulation amidst the beams and joists, &c., as a preservative from decay, and for the entire completion of the seasoning. † Price's Patent. CHAPTER III. USEFUL CHARACTERS OF WOODS. SECT. I. HARD AND SOFT WOODS, ETC. THE relative terms hard and soft, elastic or non-elastic, and the proportions of resins, gums, &c., as applied to the woods, appear to be in a great measure explained by their examination under the microscope, which develops their structure in a very satisfactory manner. The fibres of the various woods do not appear to differ so materially in individual size or bulk, as in their densities and distances those of the soft woods, such as willow, alder, deal, &c., appear slight and loose; they are placed rather wide asunder, and present considerable intervals for the softer and more spongy cellular tissue between them; whereas in oak, mahogany, ebony, rose-wood, &c., the fibres appear rather smaller, but as if they possessed a similar quantity of matter (just as threads containing the same number of filaments are larger or smaller, according as they are spun). The fibres are also more closely arranged in the harder woods, the intervals between them are necessarily less, and the whole appears a more solid and compact formation. The very different tools used by the turner for the soft woods and hard woods respectively, may have assisted in fixing these denominations as regards his art; a division that is less specifically entertained by the joiner, who uses the same tools for the hard and soft woods, excepting a trifling difference in their angles and inclinations; whereas the turner employs for the soft woods, tools with keen edges of thirty or forty degrees, applied obliquely, and as a tangent to the circle; and for the hard woods, tools of from seventy to ninety degrees upon the edge, applied as a radius, and parallel with the fibres, if so required. The tools last described answer very properly for the dense woods, in which the fibres are close and well united; but applied to the softer kinds, in which the filaments are more tender and less firmly DENSITY OF THE WOODS. 29 joined, the hard-wood tools produce rough, torn, and unfinished surfaces. In general the weight or specific gravity of the woods may be taken as a sure criterion of their hardness; for instance, the hard lignum-vitæ, box-wood, iron-wood, and others, are mostly so heavy as to sink in water; whereas the soft firs, poplar, willow, &c., do not, on the average, exceed half the weight of water, and others are of intermediate kind*. The density or weight of many of the woods may be materially increased by their mechanical compression, which may be carried to the extent of fully one third or fourth of their bulk, and the weight and hardness obtain a corresponding increase. This has been practised for the compression of tree-nails for ships, by driving the pins through a metal ring smaller than themselves directly into the hole in the ship's side; at other times, (for railway purposes,) the woods have been passed through rollers, but this practice has been discontinued, as it is found to spread the fibres laterally, and to tear them asunder; an injury that does not occur when they are forced through a ring, which condenses the wood at all parts alike without any disturbance of its fibrous structure §, even when tested by the *The most dense wood I have met with is in Mr. Fincham's collection; it is the Iron Bark wood from New South Wales: in appearance it resembles a close hard mahogany, but more brown than red; its specific gravity is 1·426, and its strength, (compared with English oak, taken as usual at 1,000,) is 1557. On the other hand the lightest of the true woods is probably the Cortiça, or the Anona palustris, from Brazil, in Mr. Mier's collection; the specific gravity of this is only 0.206, (whereas that of cork is 0.240,) it has only one-seventh the weight of the Iron Bark wood. The Cortiça resembles ash in colour and grain, except that it is paler, finer, and much softer; it is used by the natives for wooden shoes, &c. The Pita wood, that of the Fourcroya gigantea, of the Brazils, an endogen almost like pith, (used by the fishermen of Rio de Janeiro, as a slow match, for lighting cigars, &c.; also like cork for lining the drawers of cabinets for insects,) and the rice paper plant of India and China, which is still lighter and more pithy, can hardly be taken into comparison. + Mr. Annersley's Patent, 1821, for building vessels of planks only, without ribs. + Dublin and Kingston railway. § The mode at present practised by the Messrs. Ransome of Ipswich, (under their patent,) is to drive the pieces of oak into an iron ring by means of a screw press, and to expose them within the ring to a temperature of about 180° for twelve or sixteen hours before forcing them out again. The tree-nails may be thus compressed into two-thirds their original size, and they recover three-fourths of the compression on being wetted; they are used for |