Principle of the helicopter, drawing by Leonardo da Vinci
Principle of the helicopter, drawing by Leonardo da Vinci
Principle of the parachute, drawing by Leonardo da Vinci
If Leonardo da Vinci's aerial flight experiments do not seem to have been carried out on a large scale, it is perhaps not the same with the parachute, the use of which is much safer. The description of Leonardo da Vinci was reproduced later, not without a notable improvement in the mode of representation of the apparatus, in a collection of machines, due to Fauste Veranzio and published in Venice in 1617.
The Venice parachute (1617), after an engraving of the time
The attached engraving is the exact reproduction of the parachute that the author also defines in the following terms, certainly inspired by those of Leonardo da Vinci: With a square veil stretched out with four equal poles and having tied four ropes to the four quinces, a man without danger will be able to throw himself from the top of a tower or some other prominent place; because although, at the hour, there is no wind, the effort of he who falls will bring wind which will hold back the sail, lest it fall violently, but gradually descend. The man therefore must measure himself with the size of the sail.
Father Lana's aerial ship (1670)
Certainly Lana's project is impracticable: the learned Jesuit did not foresee that his empty copper balloons would be crushed by the external atmospheric pressure; but he nevertheless had a very clear idea and very remarkable for his time of the principle of aerial navigation by balloons lighter than the volume of air which they move. He ends his long chapter with some very curious considerations: I do not see any other difficulties that can be opposed to this idea, except one which seems to me more important than all the others, and that God will not allow this invention to be ever successfully applied in practice, in order to prevent the consequences which would result from it for the civil and political government of men. Indeed, who does not see that there is no State which would be insured against a stroke of surprise, because this ship would be heading in a straight line on one of its strongholds, and, landing there, could descend there soldiers.