As crooked round oak timber of the natural length is extremely unmanageable, and its distant transport very expensive, it is desirable that it be squared and cut in lengths suited to its ultimate use, where grown. This requires a thorough knowledge of the necessary curves, to which the figs. p. 19, will afford considerable assistance. However, the superintendent of any extensive fall of naval timber either should be {30} a shipwright who has had practice in lining off timbers, or should have passed several months in a dock-yard during the timbering of vessels, observing every piece that is put to use. As most part of the timbers of a vessel have their sides squared, the cutter cannot err much in hewing away the sides in the plane of, and at right angles to, the curves, at least as deep as the sap-wood reaches, thus leaving only a little sap-wood on the angles; the sap-wood, in all cases (except in those small craft used in carrying lime, which preserves from rot), being worse than useless; by its decay not only weakening the vessel from the want of entireness of the timbers, but also acting as a ferment to further corruption. In our directions for obtaining curved and angular bent timbers, we may be thought to have been a little too minute with the dimensions and figures: under the hand of the shipwright, or person of skill, a tree of almost any possible bend cuts out to valuable purpose: what is wanted is crooked timber, free of large knots;—first and second foot-hooks and knees are, however, most in demand. ENDNOTES TO PART I. [4] Beech, suited for plank, is sometimes of more value when straight and of considerable length for the purposes of keel-pieces; for this the log requires to be from 30 to 70 feet in length, and at least of sufficient thickness at the small end to square a foot. [5] These directions are generally applicable—as well for what may be required for being bent for compass-timbers, and for what may be used for land purposes, as for plank. [6] There are several valuable varieties of apple-trees of acute branch angle, which do not throw up the hark of the breeks; this either occasions the branches to split down when loaded with fruit, or, if they escape this for a few years, the confined bark becomes putrid, and produces canker, which generally ruins the tree. We have remedied this by a little attention in assisting the rising of the bark with the knife. Nature must not be charged with the malformation of these varieties; at least, had she formed them, as soon as she saw her error she would have blotted out her work. [7] Commencing by times, the greater part of training and pruning for plank, excepting in the case of dead branches, fractures, and last pruning, may be performed by a small knife.