| FIG. | | PAGE |
|---|
| 1. | —Da Vinci’s designs for human flying-gear | 9 |
| 2. | —A possible air-scout | 12 |
| 3. | —Blanchard’s flying-machine | 17 |
| 4. | —Lana’s proposed vacuum balloon | 24 |
| 5. | —Montgolfier’s experimental balloon | 34 |
| 6. | —Charles’ first hydrogen balloon | 36 |
| 7. | —Montgolfier’s passenger balloon | 39 |
| 8. | —Charles’ passenger balloon | 43 |
| 9. | —La Flesselle | 50 |
| 10. | —The Great Balloon of Nassau | 55 |
| 11. | —Car of Nadar’s balloon | 61 |
| 12. | —Diagram of a modern spherical balloon with ripping panel | 75 |
| 13. | —Blanchard’s dirigible balloon, 1784 | 80 |
| 14. | —Robert Brothers’ dirigible, 1784 | 82 |
| 15. | —General Meusnier’s proposed dirigible, 1784 | 85 |
| 16. | —Rufus Porter’s dirigible, 1820 | 87 |
| 17. | —Jullien’s model dirigible, 1850 | 88 |
| 18. | —Giffard’s steam dirigible, 1852 | 89 |
| 19. | —Dupuy de Lome’s dirigible, 1872 | 92 |
| 20. | —Renard’s dirigible, La France, 1884 | 94 |
| 21. | —La Ville de Paris | 121 |
| 22. | —Le Petit Journal, Zodiac type | 128 |
| 23. | —Clément-Bayard II, 1910 | 133 |
| 24. | —Morning Post dirigible, 1910 | 135 |
| 25. | —Route of British military dirigibles from France to England, 1900 | 137 |
| 26. | —Da Vinci’s helicopter | 175 |
| 27. | —Da Vinci’s parachute | 176 |
| 28. | —Veranzio’s parachute | 178 |
| 29. | —Lenormand’s parachute, 1784 | 179 |
| 30. | —Paper traveling parachute | 181 |
| 31. | —Wenham’s aëroplane, 1866 | 185 |
| 32. | —Penaud’s aëroplane toy, 1871 | 187 |
| 33. | —Tatin’s aëroplane model, 1879 | 188 |
| 34. | —Hargrave’s model screw monoplane, 1891 | 190 |
| 35. | —Hargrave’s kite | 191 |
| 36. | —Launoy and Bienvenu’s helicopter, 1784 | 198 |
| 37. | —Forlanini’s helicopter, 1878 | 200 |
| 38. | —Le Bris’ aëroplane, 1855 | 204 |
| 39. | —Mouillard’s aëroplane | 208 |
| 40. | —Blériot’s Toury-Artenay aëroplane circuit, 1908 | 269 |
| 41. | —Map of the “Circuit de l’Est” | 330 |
| 42. | —Diagram of Curtiss hydro-aëroplane | 333 |
| 43. | —The Etrich monoplane of 1910 | 336 |
| 44. | —Summer and winter average vertical temperature gradients | 369 |
| 45. | —General circulation of the atmosphere | 378 |
| 46. | —Normal Wind direction and velocity for January and February (Köppen) | 381 |
| 47. | —Normal Wind direction and velocity for July and August (Köppen) | 383 |
| 48. | —Trade and counter-trade winds | 384 |
| 49. | —Velocity diagram in horizontal section of a cyclone | 398 |
| 50. | —Funnel-like cloud sometimes observed in a tornado | 409 |
| 51. | —Vertical section of the St. Louis, Mo., tornado of May 27, 1896 | 411 |
| 52. | —Horizontal section of St. Louis tornado of May 27, 1896 | 412 |
| 53. | —Vertical section of short tornado | 414 |
| 54. | —Vertical section of a tall tornado | 415 |
| 55. | —Vertical section of a hail tornado | 417 |
| 56. | —Universal anemograph | 428 |
| 57. | —Records of wind variation in horizontal and vertical direction | 429 |
| 58. | —Records of Wind speed obtained by Langley | 433 |