is an invention to save labour. Without some tool the carpenter's work could not be done at all by the human hand. A knife would do very laboriously what is done very quickly by a hatchet. The labour of using a hatchet, and the material which it wastes, are saved twenty times over by the saw. But when the more delicate operations of carpentry are required--when the workman uses his planes, his rabbet-planes, his fillisters, his bevels, and his centre-bits--what an infinitely greater quantity of labour is economized, and how beautifully that work is performed, which, without them, would be rough and imperfect! Every boy of mechanical ingenuity has tried with his knife to make a boat; and with a knife only it is the work of weeks. Give him a chisel, and a gouge, and a vice to hold his wood, and the little boat is the work of a day. Let a boy try to make a round wooden box, with a lid, having only his knife, and he must be expert indeed to produce anything that will be neat and serviceable. Give him a lathe and chisels, and he will learn to make a tidy box in half an hour. Nothing but absolute necessity can render it expedient to use an imperfect tool instead of a perfect. We sometimes see exhibitions of carving, "all done with the common penknife." Professor Willis has truly said, with reference to such weak boasting, "So far from admiring, we should pity the vanity and folly of such a display; and the more, if the work should show a natural aptitude in the workman: for it is certain that, if he has made good work with a bad tool, he would make better with a good one." [Illustration: Boulton.] The Emperor Maximilian, at the beginning of the sixteenth century, ordered a woodcut to be engraved that should represent the carpentry operations of his time and country. This prince was, no doubt, proud of the advance of Germany in the useful arts. If the President of the United States were thus to record the advance of the republic of which he is the chief, he would show us his saw-mills and his planing-mills. The German carpenters, as we see, are reducing a great slab of wood into shape by the saw and the adze. The Americans have planing-mills, with cutters that make 4000 revolutions, and which plane boards eighteen feet long at the rate of fifty feet, per minute; and while the face of the board is planed, it is tongued and grooved at the same time--that is, one board is made to fit closely into another. But the Americans carry machinery much farther into the business of carpentry. Mr. Whitworth tells us that "many works in various towns are occupied exclusively in making doors, window-frames, or staircases, by means of self-acting machinery, such as planing, tenoning, morticing, and jointing machines. They are able to supply builders with various parts of the wood-work required in building at a much cheaper rate than they can produce them in their own workshops without the aid of such machinery."