INDEX

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.

Transcriber’s Notes:

Redundant title page has been removed.

Blank pages have been removed.

Silently corrected typographical errors.