No one at home or abroad has shown so much energy in the solution of the questions of high-speed air and water navigation as Santos Dumont. The rapidity with which he changes from experimentation with an aeroplane to skimming the water with a hydroplane, and then back again to an aeroplane, is truly amazing. If the hydroplane does not succeed, or if the aeroplane gets smashed, he is soon afloat or afield again with a new and improved apparatus. Only a short time ago we illustrated his hydroplane, and now we take pleasure in showing our readers his latest aeroplane, with which he has signified his intention of competing for the SCIENTIFIC AMERICAN trophy. This latest aeroplane, which is Santos Dumont's nineteenth machine, is the lightest and simplest flyer which he has thus far produced, which accounts for its rapid construction in two weeks' time. Instead of having double surfaces, as did all his previous aeroplanes, "No. 19" is a monoplane made up of two wings set at a dihedral angle. This monoplane is 5.1 meters (16.73 feet) long (spread of the wings) by 2 meters (6.56 feet) wide (from front to back), and it is mounted upon a suitable framework of steel tubing, which is in turn carried upon three pneumatic-tired wheels that are slightly inclined outward, so that they are farther apart at the bottom than at the top. A combined lozenge-shaped horizontal and vertical rudder is mounted, by means of a universal joint, upon the end of a 20-foot bamboo pole that projects behind, while a small horizontal rudder is also fitted in front. Two lozenge-shaped stabilizing rudders are placed nearly -vertical, one on each side of the supporting framework, and are arranged to work in unison with the rudder at the rear when moved by a single handle, which, when it is moved in another direction, also operates the horizontal rudders. Both the rudders and the wings of 446 the aeroplane are made of plain white silk tightly stretched over the ribs of the wooden framework, which is slightly inclined upward from rear to front. The motor is far simpler and considerably less powerful than the 8-cylinder, V-type, water-cooled engine with which Santos Dumont first flew over a year ago. It is a double-opposed-cylinder gasoline motor of the air-cooled type, capable of developing from 17 to 20 horse-power. As can be seen from the illustrations, it is mounted at the front edge of the aeroplane, and carries a 2-bladed, 4%-foot propeller directly on its crankshaft. The pitch of the propeller is 1.05 meters (3.44 feet), and the blades are oval and concave. The motor was designed and built in ten days by the engineers of the Duteil & Chalmers Company, of Paris. Its weight is but 22 kilogrammes (48% pounds), or about 2y2 to 2% pounds to the horse-power. The gasoline tank is very small. It holds only one liter (about a quart), and is fastened at the rear of the monoplane. The seat for the" aviator consists of a small saddle suspended from the framework below the aeroplane. The controlling handles for the rudders and engine are conveniently placed in front of the operator. As already stated, the whole apparatus is carried on three wheels placed underneath the chassis, and there is also a supporting piece fixed under the middle of the bamboo pole. What is remarkable about the new flyer is its small ~fcize and its compact appearance. It is much smaller than most of the aeroplanes which have been built recently. The total overall length of the machine from front to rear is 8 meters (26.24 feet). The weight is also remarkably low, and it would be difficult to construct an aeroplane much, if any, lighter, as it weighs only 56 kilogrammes (123.45 pounds) for the complete apparatus, and 110 kilogrammes (242% pounds) when mounted by Santos Dumont. The total sustaining surface of this aeroplane is about 107 square feet, so that each square foot is loaded to the extent of 21/4 pounds when the weight of the aeronaut is included. The weight lifted per horse-power is about 14:4 pounds. During the first flights which were made with his new monoplane on November 17 in the Bois de Boulogne, M. Dumont was well satisfied with its performance, about which he spoke as follows: "I had the aeroplane well under control, and never had such a great sensation of security, even in my airships. During these experiments I did not yet work the rudders, but by shifting my body to the right or left, the apparatus had a tendency to follow this movement by turning in the corresponding direction. The flight was stopped by a somewhat curious accident, that is, a lack of gasoline, as the tank had not been filled up after the first tests, so that the motor came to a stop and the flyer pointed head down; but as I was then sailing about twenty feet high, I had time to rise up again by working the horizontal rudder, and was able to come down easily on the ground." Owing' to the breaking of a wheel, the tests were stopped for that day. Santos Dumont then made his formal entry at the Aero Club in order to compete for the Deutsch-Archdeacon prize of $10,000 on the following day. To do this the aeronaut must fly across the starting linewhich line is determined by two poles placed 50 meters (164 feet) apartand then make the turn about another post situated at 500 meters (1640.4 feet) upon a line running from the middle point of the starting line and at right angles to it. After making the turn, the aeronaut must come back and cross the line while in full flight. The trial was accordingly carried out the next day at the drill grounds of Issy les Moulineaux, on the outskirts of Paris, with the posts planted and the official timekeepers present. There were many prominent aeronauts assembled, such as Messrs. Archdeacon, Henri Deutsch, Delagrange, Tatin, Henri Farman, Capt. Fer- ber, and two representatives of the SCIENTIFIC AMERICAN. After making a preliminary run upon the ground, he made a fine flight of three hundred feet or more at twenty feet height; and then a second flight of about the same distance, keeping at fifteen feet from the ground. The best performance was a flight of 450 feet made quite near the ground, during which he changed the height from five to six feet at will by means of the horizontal rudders. After changing the direction of the posts so as to bring the wind dead ahead, he attempted to make an arc of a circle, being part of the time in flight and the remainder on the ground; but after several attempts of this kind he found that he was hindered by the faulty working of the carbureter, which was at too high a level for the gasoline to flow into it properly. For this reason he was obliged to finish the test for that day. Henri Farman expected to begin work the next day, so that it was agreed that the two aeronauts should compete for the prize on alternate days. On November 21 Santos Dumont again tried his machine in the presence of the Aero Club committee. After two or three unsuccessful attempts to get the aeroplane up in the air, he finally made several short flights of from 90 to 120 feet. Just as the machine landed after one of these, a propeller blade broke off, and, hurtling through the air for a distance of 393 feet, buried itself in the turf. The aeroplane fell over on one wing and stopped abruptly. Although Santos Dumont escaped injury, the motor broke loose, and the machine was rather badly damaged. TEST OF THE BELL AEROPLANE. On the sixth instant Dr. Alexander Graham Bell's tetrahedral-cell aeroplane was successfully flown as a kite above the Bras d'Or lakes at Baddeck, C. B. The aeroplane carried ballast representing a man and motor. It rose in the air easily when towed at a speed of about 15 miles per hour. Dr. Bell was entirely satisfied with the result of the test, which was made before fitting the aeroplane with a motor.