Page:Encyclopædia Britannica, Ninth Edition, v. 2.djvu/336

Rh 316 ABBOBIGULTURE bark of the larch is of considerable value in tanning ; and as the leaves are deciduous, grass grows better under its shade than under any other species of pine. The larch is readily increased by seeds, which ripen abundantly in Britain ; it prospers best in cool argillaceous soil, moist rather than dry, and at a considerable elevation above the sea. In certain soils, it is subject to decay of the heart- wood ; and of recent years disease has seriously affected many of the finest plantations in this country, especially those beyond the age of fifty years. The larch is indigenous in the alpine region of Central Europe, and is a striking example of the successful introduction of an exotic, having been completely naturalised in Scotland for more than a century. Other species of Larix, natives of Siberia and North America, are inferior as forest trees. The SCOTCH PINE (Pinus sylvestris, L.) is, next to the larch, the most valuable coniferous tree grown in Britain. It furnishes the yellow deal of the Baltic and Norway, which is unequalled by any other pine in Europe or North America. The best grown in Britain is produced in the native Highland forests ; but there is reason to believe that artificial plantations, in similar soils and situations, would produce timber of nearly equal value. This tree is readily increased from seeds, which, unfortunately, are produced in the greatest abundance on stunted or inferior trees. It is very desirable to select seeds from the best varieties, as is now systematically done by nurserymen. The Highland variety with horizontal branches is that of highest repute. The Scotch fir is a native of Europe and Asia, but not of America. The CLUSTER PINE (Pinus Pinaster, Sol.) is not adapted for general culture in Britain, and therefore scarcely merits to be ranked among British timber-trees. In some parts of the east coast of England, however, plantations of this tree have been raised ; and in deep sandy soil it produces a considerable bulk of timber in a short time, thriving better when exposed to the sea-breeze than any other pine. The wood is not so durable as that of the Scotch pine ; but it may be employed in the joinery of ordinary apart ments. In general, however, it is not sufficiently strong for the roofing, joists, and other carpentry of dwelling- houses. In France, and particularly in the neighbourhood of Bordeaux, it is extensively grown on the sandy wastes, for the production of resin, tar, and pitch, which are obtained by incisions made in the trunk, and by subjecting the wood to the action of fire. The seeds are ripened in England. The young plants require more care in trans planting than those of most other pines, being furnished with a stronger tap-root. The cluster pine is a native of the south of Europe and Algeria. The SPRUCE FIR (Abies excelsa, D.C.) is, as a British timber-tree, next in value to the Scotch pine. The young plants and the spray are durable ; and the trunk grows straighter, more erect and slender, than the larch. The trunk is seldom sawn into boards ; the great value of the tree being for poles of every kind, from those fit for the hop up to masts for smaller ships. It is often used with the bark on, for poles or fence-wood. In most parts of Europe, the poles used in the scaffolding employed in erecting buildings are formed of this tree, the wood being light and elastic. The spruce fir ripens seeds abundantly in Britain, from which plants are as easily raised as the Scotch pine and the larch. It prefers a rather moist soil, and only attains a great height in sheltered situations ; but it grows anywhere to a size fit for hop-poles or fencing in a short time. Like the Scotch pine, it is subject to few diseases. The spruce is a native of Germany, Sweden, Russia, and Norway, but not of Britain or of North America. The SILVER FIR (Abies pectinata, D.C.) the largest of the European conifers, in various soils and situations produces a great bulk of timber in a comparatively short period ; the timber is considered less strong and durable than that of the spruce fir or the Scotch pine, but it does not warp, and is adapted for all kinds of carpentry. The timber is white, and when not exposed makes excellent flooring. The tree is of slow growth for the first ten or twelve years ; nevertheless, even in the north of Scotland it attains the height of 100 feet in sixty or seventy years. It ripens seeds in Britain, but more sparingly than the spruce fir, and plants are easily raised. It is in general healthy, but its cultivation is more difficult than that of the spruce, as the shoots of young trees are liable to be killed by frost. This species is also very subject to the attacks of an insect, Eriosoma, which often causes the death of the tree. The silver fir is a native of Central Germany, and of tha mountains of Italy and Spain. Nearly allied is the Abies balsamea, balm of Gilead fir, a native of North America, which produces the Canada balsam, but it cannot be recommended for cultivation, as it is short lived. Many conifers might be mentioned which, though not pro ducing timber in Britain, are worthy of cultivation. Of the American pines we have the Pinus Strobus, L., Weymouth pine, which furnishes the white wood of Ameri can commerce. Several Californian pines have been introduced; of these Abies Douglasii is the most promising. Cupressus Lawsoniana is a beautiful tree, and also Sequoia gigantea, the mammoth tree, a general favourite in pleasure grounds, but a considerable period must elapse before wo can judge of their being adapted for general culture as timber trees in this country. Of Asiatic conifers, Ccdrus Deodara and Libani are much grown for ornament. Pinus excelsa, which resembles the Weymouth pine, and Abies Smithiana and Webbiana grow fairly in many parts of Britain ; the Smithian pine being apparently the best adapted to the climate. The YEW TREE (Taxus baccata, L.) attains its full per fection in this its native country ; but on account of its slow growth it cannot be recommended to the planter, whose main object is profit. Broad-leaved Trees (bois feuillus) in contradistinction to needle-leaved, are classed, according to their timber, in two subdivisions, hard and soft wood trees. They are character ised by large trunks and widely spreading woody branches, and broad leaves with branching veins; they send up shoots from the stool when cut over by the ground ; and they are deciduous. They belong to the Dicotyledons. 2. Hard-wood Trees. The hard-wood Timber-trees of Great Britain are charac terised by the comparative hardness and durability of their wood, and comprise the oak, ash, elm, beech, sweet chestnut, walnut, and Kobinia or false acacia. The British oak includes two sub-species, the stalked fruited or most com mon oak, Quercus pedunculata, and the stalkless fruited or less common oak, Quercus sessiliflora. The latter grows more erect and more rapidly than the other, particularly if the soil be good. In England and the lowlands of Scotland, Q. pedunculata is the commoner of the two oaks ; but in North Wales and the hill parts of northern England, Q. sessiliflora is more frequent. Intermediate forms between these two oaks are found in England and elsewhere, and the leading botanists of the day unite them under the old name of Q. Kobur. The wood of the oak is the strongest and most durable of all British timber-trees ; but on account of the slowness of its growth it is not always the most eligible for planting. Oak plantations are more valuable than others when in a young state, on account of their bark. From the demand for oak as ship-timber, the price of trees fit for that purpose is always considerable ; but the largest trunks employed in naval architecture do not