e;—3e

6

now tightly packed in tHe cavity, ends downwards, until it is completely filled, when the surface is covered with turf, which is compactly beaten down by two men, one of whom uses a wooden stamper, the other a wooden mallet, so that the outer surface is sufficiently firm to prevent the escape of the volatile products. It is absolutely necessary that this part of the process should, be efficiently performed. A small portion of the turf is now removed and fire applied to the stack: as soon as it is kindled the turf is replaced. The exuded tar is received into the pan at the bottom of the hole, and is discharged by the spout into casks, which are at once bunged and made ready for shipment. The quantity of billets subjected to slow combustion at the same time is frequently enormouß, amounting to 50,000 or 60,000 cubic feet. In this case the pile rises considerably above the surface of the cavity, but the whole must be carefully covered with sods, &c, as already described. A pile containing 50,000 cubic feet requires a fortnight for the process of combustion. It need scarcely be remarked that the wood must be dry before the operation is commenced. In the highlands of Scotland tar is sometimes extracted by a somewhat rougher method. A hole is dug in the side of a hill, a gutter being formed at the bottom of the hole, and terminating in a small aperture outside. The hole is filled with wood cut to proper lengths, and the top is covered with tiles or sods. The tar gradually drains into the gutter, and is discharged by the external aperture, which must, of course, bo very small, or air will be admitted in such quantity as to bum the entire mass. Pitch. This is obtained by boiling wood-tar until nearly one-half of its bulk has evaporated, when the remainder is allowed to cool and harden into pitch. The process is usually effected in copper boilers set in brickwork, to diminish the risk of accident. Lampblack. This is merely the fine soot given off during the manufacture of tar or charcoal. It is deposited on the sods which cover the billets, and must be scraped off. If, instead of the rough processes described above, closed ovens were used, the lampblack would be deposited on the roof. A superior kind is manufactured in a more systematic manner from the straw and other waste material used in the preparation of the resin of the pinaster. A small furnace, about 4ft. in length and 2-J-ft. in width, is set in brickwork ; on each side of the furnace, near the bottom, is an opening fitted with a close-fitting door. The chimney, which is nearly horizontal, conducts the smoke into the centre of a small wooden chamber, about 12ft. square and 10ft. in height, with a hole in the roof about 6ft. square. The chamber is entered by a door working in a groove and so fitted as not to allow the escape of smoke at its joints. The walls and roof are lined with boards on the inside. The opening in the roof is covered by a double thickness of coarse flannel sewn into a conical or pyramidal shape, and supported on a light wooden framework. The straw and waste material from the manufacture of tar and resin is placed in the furnace in small quantities, merely sufficient to keep the fire alight, the supply being constantly maintained. The smoke passes into the boarded chamber, and the soot is deposited partly on the boards and partly on the flannel cone, while the lighter portion of the smoke filters through the latter, which also allows the heated air to escape. The lampblack is detached by striking the boards and flannel with a stick, when it falls to the ground, and is collected into small casks for shipment. In some parts of Germany the furnace and chamber are constructed in a large shed ; but in Bordeaux the whole is exposed, the chamber being covered with a tiled roof. It is obvious that a chamber of this kind might readily be constructed of corrugated iron. Eesin. Eesin, or rosin of commerce, is obtained from various pines in Europe and America. The kauri resin, popularly called kauri gum, is one of the most valuable known, and it may be partly due .to the fact of its value, and its abundance in the northern districts of the colony, that no attention has been paid to that produced by the rimu, the kahikatea, and other trees. The greater part of , the kauri-gum sent into the market is found in a fossil condition, a very small portion being the produce of living trees, although occasionally it occurs in recent masses or " tears " of several pounds' weight at the junction of a large branch with the stem. Although a " shake " or fissure of any kind in the trunk of the red-pine (rimu), or white-pine (kahikatca), is always found to be compactly filled with resin, no attempt has been made to collect it for commercial purposes; it may therefore be worth while to describe the mode of extraction practised in Southern Europe. In the Landes of Bordeaux the pinaster has been largely planted to fix the blown sand ; the plantations thus formed not only yield a supply of useful timber and firewood, but afford support to a large portion of the population engaged in the collection of the resin. In May, a piece of the outer bark, about Sin. wide and 20in. long, is stripped from the trunk just above its base ; a cavity sufficiently large to hold a half-pint of sap is cut in the trunk at the bottom of the place thus laid bare, or a trough may be attached on the outside. Above the trough or cavity the Inner bark is removed to the width of 4in. and the height of 6in. The resin escapes from bstween the inner bark and the wood, and is conducted to the trough, which is emptied at regular intervals. The surface of the wound is lightly chipped over once a week until the close of September so as to expose a fresh surface; by this means its dimensions are gradually increased, .but it is not allowed to exceed 6in. in width and 18in. in length. The following spring a new piece of bark is stripped off immediately above the old wound, and the process is repeated yearly until the incision is carried to the height of 15ft. or thereabouts, according to the strength of the tree, when a new incision is made at the base parallel with the old one, but leaving