Do.   Marey, [226]

Do.   Chabrier, [233]

Do.   Straus-Durckheim, [233]

Do.   how to apply to the air, [245]

Do.   nature of forces required to propel, [246]

Artificial wave wing of Pettigrew, [236]

Do.   how to construct on insect type, [240]

Do.   how to construct to evade the superimposed air during the up stroke, [241]

Do.   can create currents and rise upon them, [253]

Do.   can be driven at any speed; can make new currents and utilize old ones, [251], [255]