The salient features of the machine are the backward slope of the planes, which, in plan view, form an angle with the apex in the direction of flight, and the absence of a tail or supplementary planes of any description. The following are its chief dimensions:--Span, 46 feet; length (fore and aft), from apex to rear wing tip, 20 feet 4½ inches; length of body, 19 feet; surface, 500 square feet; weight (including pilot and six gallons of petrol), 1,700 lb.; engine, four-cylinder 50–60 h.p. Green, 1,100 r.p.m., driving twin propellers placed one on either side of the body in the rear. The weight in flight being 1,700 lb., the aëroplane carries a load of about 3 lb. per square foot. The speed in flight averages about 40 m.p.h. The chord of the surfaces is even throughout--6 feet; the vertical distance between the surfaces is also constant at 6 feet; at either extremity a vertical curtain is placed between the surfaces to prevent leakage of air sideways. The surfaces slope back from the apex at an angle of 58° on either side, the rear wing tips, therefore, actually being in the rear of the aft end of the body, and the entire outer extremities of the wings lying back well behind the centre of gravity. The curve or camber of the planes is not uniform, and, briefly, it may be said that each wing may be viewed as a portion of the surface of a cone with the apex to the rear. A consequence of this is that the angle of incidence of each wing gradually decreases from the root to the tip; so much so, that while the angle at the root is positive, that at the tip is distinctly negative, the difference in the respective angles being 45°. Apart from this, an interesting feature is the extreme downward bend of the _trailing_ edges over a short distance where the two surfaces meet in the centre; this arrangement has been adopted chiefly to enable the aëroplane to right itself naturally in the event of its having assumed a vertical position in the air. A further interesting consideration is that this machine is the only one that could safely be forced backwards. It may be added, briefly, that the loss in efficiency arising from the negative angle of the wing-tips is compensated by the backward slope and angle of the surfaces, which naturally causes the flow of air to be depleted outwardly beneath the planes, and even induces a certain amount of compression beneath the outer ends. The body is entirely covered in; the pilot’s seat is in the prow; the motor further to the rear. The centre of gravity is well forward, and about six inches above the lower plane. The propellers are carried on a transverse girder, and are chain-driven in the same direction--contra-clockwise viewed from the rear. The centre of the boss is situated 1 foot