The sliding-seat apparatus consists of a seat provided with four wheels, two on either side, which rest upon two parallel rails. These are joined together by crossbars and the path for the wheels is slightly sunk. From the under surface of the seat projects a pair of right-angled metal bars, the free ends being lodged in shallow grooves on the inner sides of the rails. These ensure that the seat will not "run loose" over the side of the rails.

One end of the rails rests upon the metal rod already mentioned as taking the place of the lowest rung of the ladder. The other end rests similarly on a corresponding rod which passes through two wooden uprights. The latter are supported on a movable base-board, and are drilled with seven holes placed opposite to each other. It is thus possible to raise the inclination of the rails from the horizontal to a very considerable angle. To the sides of the rails near the ladder are attached a pair of semi-circular uprights through which pass a horizontal metal bar. This can rotate freely, but its movement can be controlled absolutely by means of a thumb-screw. To the front surface of this bar is attached a plain piece of wood, fitted along the lower border with semi-circular heel rests. This provides a foot-piece that can be adjusted to any angle. It will be seen, therefore, that this apparatus possesses two great advantages over the common marketed designs, namely, that the inclination of the rails can be adjusted to the most suitable angle, and that the foot-piece can be placed in the most advantageous position.

When not in use the loose poles can be suspended from two slots placed one on either side of the top of the main box; the wrist-machine can be suspended from a short metal rod attached to the side of this box, and this runs through a circular hole cut in the wooden back-support of the apparatus; while the under surface of the rails of the sliding-seat apparatus is provided with a metal hook on either side which can be fitted over one of the rungs of the ladder.

The main drawings are shown to a scale of 1/2 inch to I foot, and the numbers refer to the figures on the subsequent pages. These detailed drawings are all shown one-third full size.

The apparatus has been placed on the market, with slight alterations, by Messrs. Spencer, Heath and George.

The last drawing (No. 12), drawn to a scale of 3/8 inch to 1 foot, shows the details of the table we are now using for the flexion deformity of amputation stumps. It has been fully described in the text (see p. 479).

Details of Construction of the Table used for Stretching Amputation Stumps.

1 have received so many inquiries as to what work is done in the elementary class-room at the Special Surgical Hospital that I have asked Miss Simpson (who has organised and controlled this work so admirably since May, 1917) to draw up in rough outline a series of exercises. I am indebted to her for the contents of this Appendix. I was so greatly impressed with the necessity of providing active exercise under trained and skilled supervision at the earliest possible date after the receipt of injury that I instituted these elementary classes for the use of patients who were fit to perform any degree of active movement in safety, but who were, for various reasons, unable as yet to take their place in the gymnasium. The class-room is in fact a sort of nursery in which patients are either tested as to their fitness for the gymnasium, or in which they are trained until fit to proceed there. In an elementary knee class, for instance, it may often be found that not one of the patients in the class is yet allowed to put the full weight of his body on to the injured limb; in a foot class a man is often found who is not able to stand. Patients frequently attend an arm or hand class while still wearing abduction or cock-up splints. The institution of these classes has, I think, done more than perhaps anything else to impress upon many patients two vital facts: first, that there is really a chance of ultimate recovery, and, second, that recovery depends to a great extent on their own individual effort. This was their object and, thanks to the loyal help and co-operation of Miss Simpson and those who have worked with her, the experiment has received ample vindication.