_In pruning and educating for plank timber, the whole art consists in training the tree as much as possible, and with as little loss of branch as possible, to one leader and numerous feeders, and to the regular cone figure which the pine tribe naturally assumes._ This can be best and most easily performed by timely attention—checking every over-luxuriant, overshadowing branch and wayward shoot on its first appearance; so that none of the feeders which spring forth at first may be smothered, till {14} they in turn become lowermost; and by the influence of rather close plantation, which of itself will perform in a natural manner all that we have been teaching by art, and will perform it well. This closeness must, however, be very guardedly employed, and timeously prevented from proceeding too far, otherwise the complete ruin of the forest, by premature decay or winds, may ensue, especially when it consists of pines. Of course all kinds of pines require no other attention than this (well-timed thinning), and to have their sickly moss covered under branches swept clean down. SECTION II. TIMBERS. Timbers, as before stated, are the ribs of the vessel, spreading out and upward (excepting at the bow and stern) at right angles to the keel and keelson, two large straight logs which form a double spinal support or backbone. The ribs or compass timbers in great public building establishments are sometimes bent by machinery, after being softened by steam or hot liquids[8]; and for this purpose the {15} cleanest straightest wood is requisite. We, however, do not believe that pieces of great diameter, bent artificially, can have equal strength and resilience as when grown bent—the fibre must in some degree be crippled. We admit that timbers and frames may be built of separate bended pieces of no great thickness, and have all the strength and resilience of natural bend: the strongest and most elastic mode of forming vessels would be to compose them of different layers of plank over each other in diagonal fashion, or at an angle 60°, but the labour and inconveniency of these modes would be great. We will not admit that an experiment between the strength of a piece of coarse cross-grained timber, half naturally bent, half cut out of the solid, and that of a piece of clean timber artificially bent, is any proof on the subject. Let us produce a clean natural bend, exactly fitted to its place, without any section of fibre, and make experiment with it. But at any rate, as this plan (bending of timbers) has never been adopted to any extent in our private building-yards, we must doubt its economy,—either {16} that the practice is of no considerable advantage, or that the requisite machinery is too expensive for private establishments, and conclude that fine bent timber still continues a necessary in the formation of at least our mercantile marine.