He suggested the use of experimental tanks for testing the powers of ship models, invented an ear-trumpet for the deaf, improved the common house-stove of his native land, cured smoky chimneys, took a lively interest in machine-guns and even sketched a flying machine.
The ship floats upon water and the balloon upon air; but the ship differs from the balloon, and the ship and the balloon differ from the flying creature and flying machine.
The analogies which connect the water with the air, the ship with the balloon, and the ship and the balloon with the flying creature and flying machine are false analogies.
A sailing ship is supported by the water and requires merely to be propelled; a flying creature and a flying machine constructed on the living type require to be both supported and propelled.
The physical properties of water and air explain in a great measure how the sailing ship differs from the balloon, and how the latter differs from the flying creature and flying machine constructed on the natural type.
