The durability of the wood of the larch is well known, and this peculiarity is even noticeable when of only a few years’ growth. As compared with Scotch and spruce firs, the wood of the larch is about twice as durable—a fence of the latter cut at from twenty to thirty years’ growth lasted from seventeen to twenty years, while that of the spruce lasts about eleven years, and the Scotch seven years. This refers especially to rails, not to posts, which decay in about half that time. For mining and railway purposes the durability of larch wood makes it much sought after, this being further enhanced by its extreme lightness, the weight of a cubic foot when seasoned being only 34 lbs. It takes a beautiful polish, works with great freedom, and, when fully seasoned, is not at all liable to twist or warp. Substitutes for the larch have often been recommended, but, in the true sense of the word, there are practically none, although, doubtless, some of those whose claims have been set forth might to a certain extent reflect one or more of its valuable qualities. =Sitka or Silver Spruce= (_Picea Sitchensis_).—From a purely commercial point of view the Sitka or Silver Spruce is probably the most valuable of any of the family to which it belongs. It is a tree of noble growth in this country, several specimens being well over 100 ft. in height and with boles that girth fully 10 ft. at a yard from the ground, these dimensions being attained in seventy-five years. When used as a standard, the tree is one of great beauty, the stiff and rather irregularly disposed branches being thickly beset with vivid bluish-green foliage that is silvery on the under side. It delights in a cool, moist loam and not too exposed situation, but when grown on gravel or any warm soil the foliage is distinctly meagre and affected by red spider. The timber, which is remarkably light for its bulk, strong and flexible, is of great value in the making of aeroplanes, and special logs find a ready market at highly remunerative prices in the London market. The =Corsican Pine= (_Pinus laricio_).—This is, undoubtedly, one of the best all-round conifers that has found its way into the British Isles. It is of very rapid growth, and well suited for planting, even in the most exposed and wind-swept situations; a non-fastidious subject as to soil, and a valuable timber-producer.