No. XV.
A way how to make a boat work itself against wind and tide, yea, both without the help of man or beast; yet so, that the wind or tide, though directly opposite, shall force the ship or boat against itself; and in no point of the compass, but it shall be as effectual as if the wind were in the poop, or the stream actually with the course it is to steer, according to which the oars shall row, and necessary motions work and move towards the desired port, or point of the compass.
NOTE.
A Panemore, or globular wind-mill, erected in the centre of a ship, has been proposed for the turning of two wheels or paddles, placed on the bows, which would thus impel the vessel forward in any required direction. The panemore, which was invented by M. Desquinemare, consists of a kind of globe placed on the top of a mast, on which it always turns round with the wind. In consequence of the ingenious adjustment of the curves which it presents in all its points, the rotary motion is always in the same direction, be that of the wind as it may; and their utmost violence, instead of being detrimental to its action, only augments its power. The means of the instrument increasing in a cubical ratio when the wind doubles its velocity; and by doubling the surface its power is increased eight-fold.