1. The written history of sulfuric acid dates from the sixteenth century; its preparation and reaction with iron to form hydrogen before that time is speculation but plausible.
2. J. R. Partington, A History of Chemistry, 4 vols. (London: Macmillan, 1961), 2:526; Philosophical Transactions (1766): 141; Cavendish's papers are in The Scientific Papers of the Honourable Henry Cavendish, F.R.S., Sir Edward Thorpe, ed., 2 vols. (Cambridge: University Press, 1921). Volume 11, Chemical and Dynamical, was the source used. See also Partington, History of Chemistry, 3:302-62.
3. Tiberius Cavallo, The History and Practice of Aerostation (London, 1785), pp. 51-61, 97-107; Encyclopaedia Brittanica, 11th ed., s.v. "Aeronautics"; E. Charles Vivian, History of Aeronautics (New York: Harcourt, Brace & Co., 1921), pp. 319-25; L. T. C. Rolt, The Aeronauts: A History of Ballooning, 1783-1903 (New York: Walker & Co., 1966), pp. 31-35, 49-54; Robert Jackson, Airships.: A Popular History of Dirigibles, Zeppelins, Blimps and Other Lighter-Than-Air Craft (Garden City: Doubleday & Co., 1973), pp. 7-10, 17-18.
4. Enc. Brit., 11th ed., s.v. "Aeronautics"; Rolt, Aeronauts, pp.90-93.
5. Partington, History of Chemistry, 3:445-48; Rolt, Aeronauts, p.246; Enc. Brit., 11th ed., s.v. "Hydrogen."
6. Some early measurements of hydrogen's heat of combustion, in 106 J/kg, are: Crawford (1788), 174; Dalton (1808), 106; Rumford (1812-1814), 79; Despretz (1828), 97; Dulong (1838), 145; and Berthelot (ca. 1869), 122; Partington, History of Chemistry, 3:426-34, 370-71, 156-57. For the modern value: Sanford Gordon, NASA-Lewis, to author, 9 Dec. 1974.
7. Enc. Brit., 11th ed., s.v. "Gas Engine."
8. Partington, History of Chemistry, 4:289-91, 630-31.
9. Francis Bacon, "Sylva Sylvarum or a Naturall History. In Ten Centuries," 1627, as quoted by James Dewar in his "History of Cold and the Absolute Zero," Presidental Address before the British Association for the Advancement of Science, Belfast, 1902; rev. for the Annual Report of the Smithsonian Institution for 1902 (Washington: 1903), pp. 207-08.
10. Georges Claude, Liquid Air, Oxygen, Nitrogen (Philadelphia: P. Blakiston's Son, 1913), pp. 75-79, fn. p. 80.
11. Ibid., fn. p. 88.
12. James Dewar, Collected Papers of Sir James Dewar, ed. Lady Dewar (Cambridge: University Press, 1927), pp. 678-91.
13. Scientific American Supplement, 29 Jan. 1910, p. 69.
1. The material on Tsiolkovskiy's life and works is drawn from the following sources: K. E. Tsiolokovskiy, Works on Rocket Technology, ed. M. K. Tikhonravov, NASA Technical Translation F-243 (Washington, 1965); K. E. Tsiolkovskiy, Collected Works of K. E. Tsiolkovskiy, ed. A. A. Blagonravov, vol. 2: Reactive Flying Machines, NASA Technical Translation F-237 (Washington, 1965); N. A. Rynin, Interplanetary Flight and Communication, vol. 3, no. 7, K. E. Tsiolkovskii: Life, Writings, and Rockets, translated by Israel Programs for Scientific Translations (Jerusalem: IPST, 1971); Prof. Kosmodemyansky, Konstantin Tsiolkovsky: His Life and Work (Moscow: Foreign Languages Publishing House, 1956); K. E. Tsiolkovskii, "An Autobiography," Astronautics 4 (May 1958): 48, which is also in Rynin, Tsiolkovskii: Life, Writings, pp. 2-8; and A. A. Blagonravov, ed., Transactions for the First Lectures Dedicated to the Development of the Scientific Heritage of K. E. Tsiolkovskiy, NASA Technical Translation F-544 (Washington, 1970).
2. Rynin, Tsiolkovskii: Life, Writings, p.4.
3. Tsiolkovskiy, Reactive Flying Machines, pp.82-84.
4. The first two series of numbers can be found in Tsiolkovskiy, Reactive Flying Machines, pp. 9, 170.
5. Kosmodemyansky, Tsiolkovsky, p.13.
6. Tsiolkovskiy, Reactive Flying Machines, pp.72-117; Tsiolkovskiy, Works on Rocket Technology, pp.24-59.
7. Tsiolkovskiy, Reactive Flying Machines, pp.78-79.
8. Ibid., p. 119; Rynin, Tsiolkovskii: Life, Writings, p.32.
9. Tsiolkovskiy, Work on Rocket Technology, p.35, which appears in shorter form in Tsiolkovskiy, Reactive Flying Machines, p.86.
10. Ibid. He seems to have used oil and petroleum as synonyms.
11. Tsiolkovskiy, Reactive Flying Machines, p. 122.
12. Ibid., p. 330.
13. Ibid., pp. 452, 459.
14. Ibid., p. 516.
15. Ibid., pp. 503-15.
16. Ibid., p. 513,
17. Milton Lehman, This High Man (New York: Farrar, Straus, 1963); Robert H. Goddard, The Papers of Robert H. Goddard, 3 vols., ed. Esther Goddard and G. Edward Pendray (New York: McGraw-Hill, 1970); Eugene M. Emme, "Yesterday's Dream, Today's Reality," The Airpower Historian, Oct. 1960, pp. 216-22.
18. Goddard noted the anniversary of his cherry tree dream for four decades. Like Tsiolkovskiy, Goddard's first space ships involved centrifugal force. Milton Lehman, This High Man, pp. 28, 263.
19. Goddard's undergraduate thesis: "On Some Peculiarities of Electrical Conductivity Exhibited by Powders and a Few Solid Substances" ( 1908); his Master's thesis: "Theory of Diffraction" (1910); his doctor's thesis: "On the Conductivity at Contacts of Dissimilar Solids" (1911); his post-doctoral thesis: "The Positive Result of Force on a Material Dielectric Carrying a Displacement Current" (013). Lehman. This High Man, pp. 50, 56-59.
20. Goddard, Papers, pp. 14, 22, 34.
21. Ibid., p. 121.
22. Ibid., pp. 162-74; Robert H. Goddard, "A Method for Reaching Extreme Altitudes," Smithsonian Miscellaneous Collections for 1919. Hydrogen-oxygen was not mentioned in the 1916 report but was included in supplementary notes when published in 1919. Goddard, Papers, pp. 22-23.
23. Goddard, Papers, p. 416.
24. Lehman, This High Man, p. 125; Goddard, Papers, pp. 499-506, Emme, "Yesterday's Dream," p. 219.
25. In a conversation with the author on 6 Mar. 1974, Mrs. Goddard stated that Goddard definitely did not work with liquid hydrogen; be had a hard enough time getting liquid oxygen for his initial experiments with it. He often told her he would like to have some liquid hydrogen. His first liquid oxygen came from a professor at Harvard or MIT who was conducting experiments involving liquefying air arid throwing away the liquid oxygen. Goddard went to get the excess liquid oxygen and hurried back before it evaporated. Sometimes he sent a mechanic for the oxygen. Later, Linde opened a plant in Massachusetts and Goddard began obtaining his liquid oxygen from that source.
26. For Oberth's life and work: Hermann Oberth, "From My Life," Astronautics 4 (June 1959): 38-39; Hermann Oberth, Rockets in Planetary Space, NASA trans. TTF-9227, 1965; Hermann Oberth, Ways to Spaceflight, NASA trans. TTF-622, 1972; Willy Ley, Rockets, Missiles, and Space Travel (New York: Viking, 1951, 1961).
27. M. Subotowicz, "The Rocket Conceptions of K. Siemienowicz, 1650," Jour. British Interplanetary Soc. 14 (Sept.-Oct. 1955): 245-47.
28. Oberth, Ways to Spaceflight, p. 42.
29. Ibid., pp. 38-41.
30. Ibid., pp. 94-95, 343.
31. Ibid., pp. 319, 332-36.
32. Ibid., pp. 50, 369, 22.
33. Ibid., pp. 411-12.
34. Lehman, This High Man, p. 132.
35. Goddard, Papers, pp. 497-517.
1. John Toland, The Great Dirigibles: Their Triumphs and Disasters (New York: Dover, 1972); Douglas H. Robinson, Giants in the Sky (Seattle: Univ. of Washington Press, 1973).
2. R.W. Knight, "The Hindenburg Accident, "report 11, Safety & Planning Div., Bureau Of Air Commerce, Dept. of Commerce, Aug 1938. The report included a transiation of the German Commission's report as Sec. II which came to the same conclusion, pp. 63-64.
3. "Hydrogen Safety Manual,"NASA TMX-52454, 1968, PP. 3, 30.
4. U.S. Patent 130 915, 27 Aug. 1872; Paul Haenlein, Zeitschrift fur Luftschriffahrt 1, no. 8. (188): 84.
5. "Aernonautical Engineering Supplement, "The Aeroplane 18 (18 Feb. 1920): 362.
6. Richard K. Smith, First Across: The U.S. Navy's Transatlantic Flight of 1919 (Anna-oplis: Naval Institute Press, 1973), pp. 87-94; Robinson, Giants in the Sky, p.300; Kurt H. Weil, "The Hydrogen I.C. Engine- Its Origins and Future in the Emerging Energy- Transportation-Environment System," Proceedings of the Intersociety Energy Conversion Conference, San Diego, Sept. 1972, pp. 1355-63; G. F. Mucklow, "The Effect of Reduced Intake-Air Pressure and of Hydrogen on the Performance of a Solid Injection Oil Engine," Journal of the Royal Aeronauticl Society 31 (1927): 17-51; Enc. Brit., 1961, s.v. "Lighthouses"; Chief of Naval Airship Training and Experimentation to Chief, Bureau of Aeronautics, signed by B. May, 19 Mar. 1953; Harold C. Gerrish and Hampton H. Foster, "Hydrogen as an Auxiliary Fuel in Compression-Ignition Systems," report 535 in Twenty-First Annual Report of the National Advisory Committee for Aeronautics, 1935 (Washington, 1936), pp.95-510.
7. Georges Claude, Liquid Air, Oxygen, Nitrogen (Philadelphia: P. Blakiston's Son, 1913 p.92.
8. Rexmond C. Cochrane Measures for Progress: A History of the National Bureau of Standards (Washington, 1966), pp. 83-84.
9. Manne Siegbahn, "The Physics Prize," in Nobel: The Man and His Prizes, by the Noble Foundation (New York: Elsevier Publishing co., 1962), pp.492-97.
10. Adalbert Farkas, Orthohydrogen, Parahydrogsen and Heavy Hydrogen (Cambridge: University Press, 1935), pp. 1-2; Technology and Uses of Liquid Hydrogen, ed., R.B. Scott, W. H. Denton, and C. M. Nicholls (New York: Macmillan Co., 1964), pp.2-3.
11. The heat of normal-to-para conversion at 20.4 K and heat of vaporization were taken from table I, p.4, of Guenther von Elbe and Howard T. Scott, Jr.," Hazards of Liquid Hydrogen in Research and Development Facilities," ASD-TDR-62-1027, Dir. Of AeroMechanics,AFSC, Wright-Patterson AFB, OH, Dec. 1962; The Kirk-Othmer Encyclopedia of Chemical Technology, 2d ed. (New York: John Wiley & Sons, 1966), 2:338-39, gives 168 cal/gm as the heat of normal-to-para hydrogen conversion and 21.4 cal/gm as the heat of vaporization of normal hydrogen at 20.4 K. The 1 percent loss per hour is from Scott, Denton, and Nicholls, Technology of Hydrogen,pp.2-3.
12. Farkas, Hydrogen, p.115; Arne Westgren, "The Chemistry Prize," in Noble: The Man a His Prizes, pp. 379, 391; Eduard Farber, Nobel Prize Winners in Chemistry, 1901-1961, rev. ed. (New York: Abelard-Schuman, 1963), pp.207-12.
13. Westgren, "The Chemistry :Prize," pp.377-79.
14. Farkas, Hydrogen, p. 116; Farber, Nobel Prize Winners, p.138.
15. Westgren, "Chemistry Prize," pp. 379-80; Farber, Nobel Prize Winners, pp. 137-41.
16. All three methods of separating deuterium from hydrogen are described by Farkas, Hydrogen.
17. Enc. Brit., 1961, s.v. "Hydrogen."
18. Walter Dornberger, V-2 (New York: Viking Press, 1958).
19. Wernher von Braun to author, 8 Nov. 1973. All information about Thiel is based on this source.