Appendix V
Curtiss’s Experiments in Rising From the Water
During the past two years Glenn H. Curtiss, who, more than any other experimenter, has been given to developing the aëroplane for various uses, has experimented with floats for his biplane that would enable it to rise from the surface of the water. Something over a year ago he succeeded in developing a speed of about twenty miles an hour on the water, but this was insufficient to rise from the surface.
At the beginning of the new year Mr. Curtiss moved to the Pacific Coast and set about endeavoring to develop suitable floats which would make it possible for his machine to rise from the surface of the water. These experiments have been carried on at San Diego, where Mr. Curtiss is instructing several naval and military officers in the art of flying.
In his first experiments on the Pacific Coast Mr. Curtiss followed the successful experiments of this sort made by M. Henri Fabre at Marseilles, France, about a year ago, as far as the design of his floats was concerned. He constructed one large float six feet wide, five feet from front to rear, and one foot thick at its central point, and placed this under the center of the machine. The bottom of this float was perfectly flat and arranged at an incline of ten or twelve degrees. Some distance forward of the main float, at about the position of the front wheel in the land machine, another float six feet wide, by one foot from front to rear, and six inches deep, was placed; while at the extreme front end of the machine, on a special outrigger, was mounted a small elevating hydroplane six feet wide by eight inches in a fore-and-aft direction, and one and one-half inches thick. This hydroplane was fixed at an angle of about twenty-five degrees and was intended to lift the front part of the machine. A spray shield was fitted back of it, as shown in the diagram, page 333.
The first experiments were made with these new floats on January 26th last; and although they made a considerable disturbance in the water, especially at low speed, the aviator was enabled to get up a speed on the surface of about forty-five miles an hour. He found that at as low a rate as ten miles the hydroplanes (which normally were submerged) rose to the surface, while as the speed increased only the rear edges of the two main planes were required to support the machine. The aëroplane readily attained sufficient speed to rise in the air, for as the speed increased and the floats emerged from the water, the head resistance of the floats diminished and there was only the skin friction of the water on a few inches of the rear edge of these floats, plus the air resistance, to be overcome.
At the first try-out, while traveling over the water at high speed, Mr. Curtiss found himself suddenly nearing the shore, and to avoid running aground he turned his horizontal rudder sharply upward, with the result that the machine rose from the water with perfect ease. He soon alighted again, and in the second flight he made a circle and remained in the air a minute and twenty-one seconds. Two other experimental flights were made the first day, and on January 27th he made a three-and-one-half-minute flight and stated, upon alighting, that he found no difficulty in remaining aloft as long as he pleased. The machine showed a speed of fifty miles an hour in the air as against forty-five miles an hour when skimming over the surface of the water.
Not satisfied with the several floats with which he had attained his first success in rising from the water, Mr. Curtiss immediately constructed a single float twelve feet long by two feet in width and twelve inches deep. This float is built of wood and resembles a flat-bottomed boat or scow, the top being covered with canvas to keep the water from getting in. Three feet from the front end the bottom is curved upward forming a bow the full width of the float, while at the same distance from the rear the float slants downward in a similar manner.
This single float is placed under the aëroplane in such a position that the main weight of the machine and aviator is slightly to the rear of the center of the float, which causes the latter to incline upward slightly and thus gives the necessary angle for hydroplaning on the surface of the water. The weight of this new float is but fifty pounds, or less than half as much as that of the two floats that were used before.
The paint was barely dry on the new float before Mr. Curtiss had it fitted to his machine and gave it a trial. This was done on February 1st and the trial was thoroughly successful. The machine ran over the surface of the water with very much less disturbance than before and rose in the air readily. A glance at the photographs showing the new and the old floats in action will give one an excellent idea of the much less commotion caused by the single scow-shaped float. Besides being much more compact and creating less disturbance, this float or scow can be used for carrying articles or a passenger.
In order to keep the aëroplane from tilting to one side or the other, an inclined stick four feet long and three inches wide, to which is attached on its upper side an inflated rubber tube, is fastened to the front edge of the lower plane at each end. By the use of these props the aëroplane does not tip readily when skimming along the surface, even though the scow-shaped float used is but two feet in width.
After meeting with success with his new float, Mr. Curtiss, on February 17th, made more flights with the motor and propeller placed at the front of his biplane and with his seat placed at the rear of the main planes. The chief of these flights was one which he made from North Island, where he is experimenting, over San Diego harbor to the cruiser Pennsylvania. He alighted upon the surface close beside the cruiser and his aëroplane was hauled up beside the warship and placed on her deck.
After a short visit on the cruiser the aviator was again lowered to the surface in his machine. A sailor started the engine, and Mr. Curtiss flew back to his starting point in short order. The naval authorities were greatly pleased with his demonstration and it is probable that the Navy Department will purchase one of these machines in the near future and continue the instruction of its officers.
After increasing the surface of his biplane Mr. Curtiss, on February 24th, took up one of his naval pupils, Lieutenant T. G. Ellyson, as a passenger. He made a flight of one and one-half miles, rising to a height of one hundred feet and flying as slowly as twenty-five miles an hour, or as fast as fifty miles an hour, at will. Lieutenant Ellyson was seated on the pontoon below the aëroplane. He could look down in the water and see bottom at a depth of twenty-five feet, and he believes submarines can be easily located by flying over the water. The slow speed at which it is possible to fly will make the biplane especially useful for bomb dropping. As we go to press Mr. Curtiss is about to try his machine fitted with wheels and floats as well.
Footnotes
1 With apologies to the California professor who will ride on wings worked by muscular force alone.
2 Mr. A. Holland Forbes and Mr. Augustus Post, in the international balloon race of 1908, used a balloon having too long a neck, thus causing such pressure at its top as to burst the bag. A dreadful plunge ensued, landing them on a house, but without injury, as the netting and collapsed bag dampened their speed of fall. It is reported that they crashed through the skylight, and that the lady of the house regretted not being there to receive them.
3 Mechanical Principles of Flight.
4 The reader may like to know that the basis of so much confidence was that ancient Euclidean theorem connecting the surfaces and volumes of similar figures with certain powers of their homologous linear dimensions.
5 The writer has made hydrogen-inflated varnish bubbles a foot in diameter which ascended swiftly to the ceiling; also, air-inflated varnish bubbles a foot and a half in diameter which lasted an hour. These, if suitably heated, may be made to ascend; but this experiment is more difficult.
6 Both had studied science in college. Stephen was an accomplished architect; Joseph, the author of many important inventions, among others the common lamp chimney, the hydraulic press, etc.
7 A long patch on the balloon that can be ripped open for the sudden release of gas.
8 The equator of such a balloon is its horizontal great circle.
9 A similar suggestion was made by Thomas Jefferson in a letter to Prof. James Madison, and dated from Paris in 1785: “I went some time ago to see a machine which offers something new. A man had applied to a light boat a very large screw, the thread of which was a thin plate, two feet broad, applied by its edge spirally around a small axis. It somewhat resembled a bottle brush, if you will suppose the hairs of the bottle brush joining together, and forming a spiral plane. This, turned on its axis in the air, carried the vessel across the Seine. It is, in fact a screw which takes hold of the air and draws itself along by it; losing, indeed, much of its effort by the yielding nature of the body it lays hold of to pull itself on by. I think it may be applied in the water with much greater effect and to very useful purposes. Perhaps it may be used also for the balloon.”
10 La Navigation Aerienne, Gaston Tissandier.
11 The motive power equals the product of the speed and resistance. But in the assumed case, the speed is doubled and the resistance quadrupled; hence, the power required is eightfold.
12 Santos-Dumont, My Airships.
13 m3 signifies cubic meters. One cubic meter equals 35.3166 cubic feet.
14 Hangar, an airship harbor, or garage.
15 Aëronat, an airship of the lighter-than-air kind.
16 Hearne, Airships in Peace and War.
17 Over Sea by Air-Ship, MacMechen and Dienstbach, The Century, May, 1910.
18 A mathematical argument against this device is presented in Appendix I.
19 It is commonly reported by navigators that the albatross “sports in the tempest” on unbeating pinions; but it may be questioned whether any bird can make headway against the swiftest winds.
20 The “drift” and “lift” are the components of surface wind-pressure respectively in the direction of flight and at right angles to it.
21 The tandem monoplane, or two lifting planes arranged in tandem, was invented by D. S. Brown and exhibited to the Aëronautical Society of Great Britain in 1873.
22 This gasoline aëroplane model was previously tested in private many times, both with single surface wings, and with superposed surfaces.
23 Abbe, Helicopters for Aërial Research, Aëronautics, Feb. 1909.
24 L’Empire de l’Air.
25 Progress in Flying Machines, Chanute.
26 The air rises with increased temperature, hence with increased volume displacement, thus causing the wind in general to have a slightly ascending trend.
27 Aëronautical Annual, 1897.
28 Ella Tidswell, The Aëronautical Journal, July, 1909.
29 W. J. S. Lockyer, Nature, August 12, 1897.
30 Wenham used superposed planes, Stringfellow superposed planes trussed by vertical rods and diagonal wires, Phillips, Lilienthal and Hargrave superposed arched surfaces.
31 See Aëronautic Annual, 1896.
32 Aërial Warfare, Hearne, p. 77.
33 Published by the American Engineer and Railway Journal.
34 This kind of automatic stability may be called inherent stability.
35 Models embodying the above devices had been made and flown by the writer some years previously; but aside from these it is obvious that a Phillips’s aëroplane and other kinds can be effectively controlled in flight by the above-proposed three-torque system.
36 This idea was later materialized in Langley’s gasoline biplane.
37 The means for balancing here suggested in italics was claimed some years later in Mr. Hugo Mattullath’s patent application in which the inventor had the assistance of the present writer.
38 A nearly equivalent vertical surface was used in Dr. Langley’s large “aërodrome.” It was a wind-vane rudder placed well below and to the rear of the centroid, to be used in turning corners. The pressure on this rudder would tilt the aëroplane toward the center of curvature of the path, and turn it about the vertical axis, but would conspire with the centrifugal force. If placed above and forward, it would give the desired moments, but oppose the centrifugal force.
39 He died of apoplexy, January 31, 1902.
40 The first flights were to be made from the water.
41 It can be shown that the angle of flight requiring the least motive power is that which makes the wing resistance, or drift, three fourths of the entire resistance to progression.
42 Atmospheric Resistance on Even Surfaces, by A. F. Zahm, Phil. Soc. Washington.
43 The term “aërodrome” is now commonly applied to an aviation field.
44 On August 25, 1909, Louis Paulhan, in the aviation contest at Rheims, flew 82 miles in 2 hours, 43 minutes and 24 seconds, preserving his lateral balance without the aid of torsion-wing mechanism and in a turbulent atmosphere.
45 Aërial Locomotion, A. G. Bell, Washington Academy of Science, March 4, 1907.
46 The Wrights in 1910 adopted the rear horizontal and vertical rudder, thus returning to the design of their predecessors.
47 On July 18, 1905.
48 These glides were abandoned as too dangerous and roundabout, in favor of direct tentative flights with a motor.
49 Falling weights pulling a cord that accelerates the aëroplane at starting.
50 Present Status of Military Aëronautics, Journal of the American Society of American Engineers, December, 1908.
51 On September 18, 1906, Montgomery received a U. S. patent on an aëroplane having curved wings and three-rudder control, the Wright brothers having on May 22, 1906, received a patent on an aëroplane having normally flat wings and three-rudder control.
52 The daring aviator escaped without a scratch, but his propeller and running gear were damaged slightly.
53 This was an official record, but Brookins had flown 4939 feet high, at Indianapolis, on June 17th.
54 This record was made with an uncalibrated barograph, and hence was unofficial and unaccepted as a world’s record.
55 The present writer, in his paper quoted on page 229, pointed out the equilibrative and steadying quality of torsionally elastic wings, and some years previously had proved this by gliding models having sustainers with flexible rear margins.
56 The whole water vapor in the atmosphere of our latitude in summer is equivalent to about one inch of rainfall.
57 Computed by W. J. Humphreys for Moore’s Descriptive Meteorology.
58 Ferrel, Popular Treatise on Winds.
59 Solar radiation received by the earth.
60 W. J. Humphreys, Astro. Phys. Journ., January, 1909.
61 An isobar is a line of intersection of an isobaric surface with a water level surface at any altitude.
62 A Popular Treatise on the Winds.
63 The Conquest of the Air.
64 By this current John Wise, in 1870, and Walter Wellman, in 1910, proposed to voyage across the Atlantic; Wise in a free balloon, Wellman in a motor balloon with drag rope. See pp. 74, 75.
65 It is reported that once during the month of August the rainfall totaled thirty-two feet; and it is believed that the annual fall exceeds fifty feet.
66 The “eye” is most noticeable at sea, where the cyclones are more symmetrical, and particularly in lower latitudes, where they are more concentrated.
67 The destructive one that visited Galveston in 1900 is a well-known example.
68 Contributions to Meteorology.
69 Dr. W. Dauberck, Met. Zeitschrift, April, 1866.
70 Moore’s Meteorology, p. 164.
71 Von Bezold, on the Thermodynamics of the Atmosphere.
72 Chanute, Aeronautical Annual, 1897, p. 101.
73 Nature, April 5, 1883.
74 Vol des Oiseaux.
75 Internal Work of the Wind.
76 Engineering News, December 13, 1890.
77 Meteorological Journal, November, 1891.
78 On Atmospheric Movements (Abbe’s translation).
79 From Scientific American, March 13, 1909, by permission of Munn & Co.
80 For a fuller account of this fine airship see H. Peltier’s article in L’Aérophile, December 1, 1910.
81 This description and the following are from Present Status of Military Aëronautics, by Major G. O. Squier.
82 From Navigating the Air, by permission of Doubleday, Page & Co.
83 From Scientific American of March 4, 1911, by permission of Munn & Co.