THE R-E-P MONOPLANE. The Robert Esnault-Pelterie (abbreviated by its inventor to R-E-P) monoplane, viewed from above, bears a striking resemblance to a bird with a fan-shaped tail. It is much shorter in proportion to its spread than any other monoplane, and the body being entirely covered with fabric, it has quite a distinct appearance. The plane is divided into two wings, in form very much like the wings of the Antoinette machine. Their spread, however, is but 35 feet. Their depth at the body is 8 feet 6 inches, and at the tips, 5 feet. Their total combined area is 226 square feet. The body of the R-E-P machine has much the appearance of a boat, being wide at the top and coming to a sharp keel below. The boat-like prow in front adds to this resemblance. As the body is encased in fabric, these surfaces aid in maintaining vertical stability. A large stabilizing fin extends from the pilot’s seat to the tail. The tail is comparatively large, having an area of 64 square feet. Its rear edge may be raised or lowered to serve as an elevator. The rudder for steering to right or left is set below in the line of the body, as in a boat. It is peculiar in that it is of the “compensated” type; that is, pivoted near the middle of its length, instead of at the forward end. The control of the lateral balance is through warping the wings. This is by means of a lever at the left hand of the pilot, with a motion from side to side. The same lever moved forward or backward controls the elevator. The steering lever is in front of the pilot’s seat, and moves to right or to left. [Illustration: Elevation, showing large stabilizing fin; boat-like body encased in fabric; and compensated rudder, pivoted at the rear end of the fin.] [Illustration: Plan, showing comparative spread of surfaces, and the attachment of wheels at the wing tips. Graphic sketch showing elevation and plan of the R-E-P monoplane.] The motor is an invention of M. Esnault-Pelterie, and may be of 5, 7, or 10 cylinders, according to the power desired. The cylinders are arranged in two ranks, one in the rear of the other, radiating outward from the shaft like spokes in a wheel. The propeller is of steel, 4-bladed, and revolves at 1,400 revolutions per minute, developing 35 horse-power, and drawing the machine through the air at a speed of 47 miles per hour. THE HANRIOT MONOPLANE. Among the more familiar machines which have been contesting for records at the various European meets during the season of 1910, the Hanriot monoplane earned notice for itself and its two pilots, one of them the fifteen-year-old son of the inventor. At Budapest the Hanriot machine carried off the honors of the occasion with a total of 106 points for “best performances,” as against 84 points for the Antoinette, and 77 points for the Farman biplane. A description of its unusual features will be of interest by way of comparison.