female chuck is merely a ring or nut, having a screw cut through it to correspond with the male screw. The male screw chuck is used alone. The female can only be used in combination with the other, upon which it is screwed. They are both used for hard woods, ivory, and metals. A smaller pair of these useful chucks is shown at Fig. 20. They are both used in the same manner, and for similar purposes and materials as the last. The only difference is in their

mode of attachment to the spindle, the first being fitted to screw on the spindle end, whereas in the latter the male part screws into the centre-hole of the spindle.

The chuck-plate, Fig. 21, is of metal, and with a boss the same as that of the others described. It screws on to the mandril. The plate part, or surface, is larger than that of the others, and is drilled through with a number of small holes. It can be used either as a surface chuck, to which to attach thin pieces of wood by means of turner's cement, or as an attachment for rough chucks of temporary service. For this latter

purpose especially it is very useful. Four or five screws, such as are shown at Fig. A, are made to fit in common all the holes in the plate.

Any rough piece of wood which it is wished to fasten to the plate is laid on its face, and two or more holes, in convenient positions, are made in the wood by a gimlet passing through the holes in the plate from behind. The screws are then used to fasten the one to the other. These should be inserted in such positions that they may take into those parts of the wood which do not require turning, and not into any place where they would project and be in the way of the tools. The holes being made all over the plate give every chance of the screws being properly arranged.

Temporary chucks, for which this plate is used as an attachment, are merely cavities turned out of a solid piece of wood fastened to the chuck-plate, as explained. The recess or cavity-or it may be a projection to take into a cavity-is turned so that the article may fit it rather tightly. Such chucks as these are frequently required: they are principally used for holding half-turned articles whilst they are being finished.

The work to be chucked may be of either hard or soft wood, or ivory, &c.; but these chucks do not possess sufficient holding power to answer well for metals, although a chuck of hard wood is sometimes used to hold small spheres of brass whilst being turned. Wooden cup-chucks are very inexpensive, they are easily and readily made, and do not damage the tools should they inadvertently be allowed to come in contact with them. The great objection to their use lies in the

liability, or rather certainty, of their shrinking, warping, and getting out of truth and out of shape. For this reason chucks of universal use are made of metal; but when, as is frequently the case, a peculiar chuck is needed for only one or a few articles, and, these done, it is of no further service, the wooden chucks are far preferable.

Spring chucks are made of either box-wood or metal, and screw on the spindle-end. They are formed in several parts or staves, something like a cask. These staves, having considerable elasticity, spring open; so that an article to be held by one of the chucks being inserted in the mouth of the chuck, and the staves compressed upon it by means of rings which encompass the staves, is held whilst being turned. These rings are sometimes made to compress the staves by being slid towards their largest diameter. And sometimes the outside of the staves is screwed, and the ring is also cut with a corresponding screw; the staves are then compressed by twisting the ring round so as to advance it towards the largest diameter of the chuck. In some cases these chucks are very convenient, but as they have only little power of variation in size or expansion, their use is necessarily limited. Some turners, however, have such a great liking for them that they keep them in all sizes. In most cases, a chuck turned from a solid piece of wood fastened to the chuck-plate will be found to answer just as well. Split or spring chucks are used for wood and ivory, and occasionally for metals.

There are numbers of other chucks used by turners in wood and ivory, but those described are probably

amongst the best and most generally useful. Many lathes are furnished with chucks in great number and variety, but, as a rule, one half of them are utterly valueless and never come into requisition. It is a bad plan to buy too many chucks with a lathe. Turners will find it much to their advantage to purchase at first only those which are of great use and extended application, and to add other chucks as they find they require them.

Most good lathe-makers make all their work to standard sizes, and use standard Whitworth screw threads; so that any chucks purchased even years after the lathe, can generally be relied upon to fit the spindle and run true.'

As before mentioned, chucks are usually made of metal-for the larger sorts cast iron is the best material, but for some of the smaller ones, wrought iron is to be preferred. Brass is frequently used for both large and small chucks; but, beyond its nonliability to rust, it possesses no advantage over iron. On the other hand, it is much more costly, it is more easily bruised and indented, and is much more troublesome to keep clean. The hands of the workman are also somewhat soiled by touching brass, and this does not conduce to the production of clean and unsoiled work.

Chucks are generally put on by hand, the threads of the screws being well fitted, but not made so tight as to prevent this being done. The usual mode is after removing the centres and clearing away all dirt from the spindle-end and also from the chuck itselfto hold the mouth of the chuck against the nose of the

spindle by the right hand, the left hand being at the same time applied to the driving-strap, and the cone and spindle caused slowly to revolve in the same direction as for turning. After a chuck has been used for any but very light work, it will be found to be jammed up against the collar of the spindle too tightly to allow of its being started by the hands. The chucks, therefore, are all furnished with some means for applying the power of a lever to unscrew them. Those described are shown with a small hole in the bosses, in order that they may be removed by the pin and circle wrench, as shown at Fig. 22. This method is as neat and convenient as any.

Some turners are in the habit of taking up a drill or an old piece of iron and forcing it into the pin

FIG. 22.

holes; but this is a very bad practice, and is only followed by careless workmen. When this slovenly method is resorted to, the pin-hole soon becomes bruised out of shape, and so much enlarged, that the proper instrument is rendered useless. Taper-pins are not good instruments to use for this purpose, and they should be discarded, except in those cases where but little force is required, and that not frequently.

The tools required for turning soft woods are very few and simple. The professional turner seldom uses more than half a dozen, and with these he can manage to produce a great variety of work. The bobbin or