Chapter VIII.
As different materials require somewhat different management, and even in the matter of wood alone this rule holds good, it may be as well to have some idea of what is meant by hard and soft wood.
The young mechanic has most likely hitherto considered all wood under one head; but there is a vast difference, nevertheless, in the internal structure, even of such kinds as grow in England; and the woods of foreign countries differ again from these, some being of such close texture that it is almost impossible to work them with ordinary tools, and some (such as the palm) being little else than gigantic ferns, and in structure like that much-dreaded implement of flagellation—the schoolmaster’s cane.
In England the hardest wood found is that of the box-tree, the chief place of which is in Surrey, at Box Hill; it is, nevertheless, found scattered here and there in all parts of the country, but not generally of a size greater than 3 inches in diameter. It is of very slow growth, and our own country would not nearly satisfy the demand made for it by various trades. Hence a large quantity of box, of larger growth, and generally of harder and better quality, is imported every year from Turkey, to be used in the construction of blocks for engravers, who alone require many tons weight annually, and for carpenters’ rules, mallets, turned boxes, and tool-handles; to which I may add the important item of peg-tops. I fear some of my readers may think I should have placed these first on the list! Opinions, however, I imagine, differ in this particular, as in most others, and upon all subjects.
The grain of boxwood is so close and even that it is one of the most valuable turning materials we possess. It takes excellent screw-threads, provided they are not too fine; is a very general material for boxes of all kinds, and also for chucks, although there is really no reason why it should be wasted in so applying it, when other woods of less value make such efficient substitutes. Probably its use for this purpose arose from the facility with which a screw can be cut in it to fit that on the mandrel, and that it is so hard as not to allow the collar beyond the screw to make much impression upon it. In consequence, when it is well fitted, such a chuck can be screwed on many times exactly to the same point, and will continue to run true. But I myself have found that if the mandrel-screw is not very coarse, the threads cut in the inside of the chuck are apt to break off.