THE first experimenter to succeed in making an aeroplane rise from the surface of the water was the French inventor, M. Fabre, who accomplished this feat with a monoplane of his own invention the last of March, 1910. About a year later Glenn Curtiss, at San Diego, fitted a float to his biplane and made it rise from the water and alight thereon with complete success during the course of his experiments. He flew out to the cruiser “Pennsylvania” anchored off the harbor and was lifted aboard with his machine. After paying a short visit to the ship, the aeroplane was lowered once more and Curtiss flew back to his starting point wichin the harbor. During the past summer the aydro-aeroplane has been experimented with by officers of the navy and two Curtiss hydro-aeroplanes have been purchased. These machines have found favor on account of their shift control, which consists of a movable wheel in front of the two aviators and mounted upon a vertical arm pivoted at its lower end so that it can be swung in front of either man. By this means it is extremely easy to shift the control wheel of the machine from one to the other pilot whenever it is desired to do so. In their long flight from Annapolis to Hampton Roads recently, Lieuts. Ellyson and Towers found this control of great benefit, as they were able to take turns in running the machine. Quite recently Mr. Curtiss has received a large order for hydro-aeroplanes for the Russian navy, and he has sent one of his aviators to Russia to demonstrate these machines, while Capt. W. I. Chambers of our own navy believes that before long each battleship will have to carry one or more hydroaeroplanes. One of our illustrations shows Witmer skimming the surface of the waves in the Hudson River in one of the latest Curtiss machines. This biplane is mounted on a single float, the bottom of which is rounded upward at the front, while the top is rounded downward at the rear end. This float is made of wood and is 14 feet long by 2 feet wide by a foot in depth. It will sustain a weight of some 1,400 pounds without being submerged. The front horizontal rudder is mounted above the bow of the float, where it not only serves its purpose of steering the machine in a vertical plane, but also keeps the spray from striking the aviator. At each end of the lower plane there is an inclined air cylinder which acts as a buffer and buoys up the end in case the machine tips when skimming the surface of the water. Recently Hugh Robinson made a flight in one of these machines down the Mississippi River from Minneapolis, Minn., to St. Louis, Mo., for the purpose of demonstrating its use as a mail carrier. Some five thousand pieces of mail were carried, and mail pouches were taken on and put off at the various towns on the way. Another of our illustrations shows the “Pelican” of Capt. Hugh L. Willoughby. Instead of a single float, Capt. Willoughby has built two long narrow floats with upcurved bows, which match the skids on his biplane. These floats are carefully constructed and are sheathed with brass, making them watertight. Their combined weight is but 103 pounds, or some 20 pounds less than that of the single Curtiss float. They will lift 1,200 pounds without submergence. The “Pelican” was fitted with only a 30-horse-power, 4-cylinder, Curtiss motor, which was not quite sufficient to raise it from the surface of the water. Now that he has transferred his machine to Sewell's Point, Va., he expects to fit a more powerful motor, and make flights above some of the streams in that vicinity. This new hydro-aeroplane is fitted with front and rear horizontal rudders which work in unison, the front one turning up, while the rear one points down, and vice versa. This is a system which has been used for some time by Farman, Curtiss, and the Wrights, but Capt. Willoughby has secured patents upon it, both in the United States and France. The shape of these rudders is practically triangular, and they have vertical triangular fins above and below. Triangular ailerons are also fitted at the rear ends of both planes. The inventor also has perfected a new form of throttle control whose action is just the reverse of the usual arrangement, in that when the pedal is pushed the throttle is closed and the engine slows down, while a full movement of the pedal short-circuits the magneto as well. Both the Wright and the Burgess-Wright companies brought out a hydroaeroplane. A Burgess-Wright biplane, viewed from' the rear, is shown skimming the surface of the water in one of our illustrations. Like the “Pelican,” it is provided with double floats, but the skids instead of resting upon these floats, are rigidly attached bo the aeroplane by means of suitable uprights. These floats are single-step, cedar wood hydroplanes 14 feet long by 2 feet wide, and having a 44nch step placed about in the middle. A fourth illustration shows, viewed from the front and above, the Voisin hydro-aeroplane known as the “Canard” (duck) , skimming the surface of the water before soaring in flight. This biplane, which has a long body projecting forward in front, is mounted upon four floats, two of which are distinctly visible beneath the lower plane about half-way between the body and the ends. The third float is also visible beneath the body about half-way out from the front of the main planes. The horizontal and vertical rudders can be seen at the front end of the body, while the two men in the body are peering over the side as the machine travels forward. The propeller is also visible across the rear end of the body. This machine, mounted . on wheels, was described some time ago in the SCIENTIFIC AMERICAN. During the past sumimer it was fitted with Fabre floats, and has made many successful flights from the surface of the Seine, near Paris. M. Fabre's original monoplane was built on the lines of the “Canard,” and was fitted with small floats, placed in practically the same positions as they occupy in this machine. M. Fabre experimented for a long while before he was able to obtain floats that would stand the shocks of the waves and remain watertight. He finally found that several layers of veneer was the most suitable substance for this purpose. Recently the Aeronautical Society has obtained grounds at Bergen Beach, near New York, for the purpose of making it possible for its members to experiment on the water next summer. As the members are alive to the possibilities of the hydro-aeroplane, without doubt there will be a number of these machines developed next year. The advantage of the hydro-aeroplane is that it can follow water courses that cannot be traversed by motor boats, and can travel much faster than any of these craft. In case of accident or a forced landing, there is always a good place upon which to alight. There are thousands of miles of rivers and canals in the United States above which amateur aviators can fly in safety, and without doubt another year will see a great development in the popularity of the new sport of hydro-aeroplaning.