[Illustration: FIG. 162.--The termination of the forearm is a hemispherical piece of metal, furnished with a screw into which screw at will the hand, the hook or the ring.] These appliances have replaced that in which the knife or fork is attached to a block of wood which can be fitted into the palm of the hand when required. It is inconvenient to be obliged to carry these special implements about. Raynal's fork-rest has the advantage over the last mentioned that it fits any fork. Figure 161 shows very clearly its construction and the way in which it is used. The small special attachment, which is screwed in place, is not cumbersome and can quite well be carried in the pocket; it is, however, even more convenient to have an appliance which is capable of gripping the fork directly like those described previously. [Illustration: FIG. 163.--Vine dresser's hook. (Gripouilleau).] [Illustration: FIG. 164.--The branch is held in the grip by a leverage exerted by torsion.] 2. _Appliances for Workmen._--All the appliances that are attached to the arms in place of the artificial hand for performing various kinds of work are elaborated from two simple forms: the hook and the ring (for catching hold and carrying a parcel, for holding a handle, etc.). A glance at figure 162 will show the nature of these and the way in which they are used. But it will also be understood that if the simple ring and hook are useful for equally simple purposes they are altogether insufficient for skilled labourers whose work entails a certain special adroitness, e.g. joiners, locksmiths, agricultural labourers, etc. Many makers have realised this and have devised very ingenious implements, some of which we reproduce, though we are obliged to limit ourselves to certain types, for they can be varied in countless ways according to the needs of particular cases. The same workman, as we have already said, may have several appliances which he uses in turn as he needs them in the course of his work. These appliances are constructed in two ways; some are fixed to the end of the forearm and are immobile, some are attached by means of a joint or joints and are capable of rotation in various directions. (_a_) _Fixed Appliances._--We illustrate here an appliance derived from the simple hook, the _vine-dresser's claw_, devised some time ago by Gripouilleau; branches of varying size can be held while the other hand saws them or cuts them with the pruning shears (Figs. 163 and 164). This appliance of Gripouilleau, with a series of hooks, forms the basis of almost all the "pincer hands" constructed by M. Boureau and characterised by-- (1) The closure of the upper hook which is thus transformed into a ring, the two appliances being combined in one;