ans burned the Turkish fleet in the port of Tchesme, and destroyed the fortifications by the shock of the explosion.
In 1804 the loaded catamarans of Fulton were used by the English against the French fleet off Boulogne.
But little damage was done.
The experiments were repeated again and again against Le Forte Rouge at Calais, 1804 (Fulton blew up the brig Dorothea in Walmer Roads, October, 1805.
See Fulton's Torpedo war, and Torpedoes, their invention and use, by W. R. King, U. S. A., 1d.
A tunnel under the Thames, to connect Gravesend with the Essex side, was projected by Ralph Dodd, Esq., in 1798.
In 1804, Mr. Chapman proposed to tunnel below the river from Rotherhithe to the north bank.
In 1807 the work was actually commencr-body.
Twin-screws were used upon the earliest practical propeller steamboat, that of Colonel John Stevens of Hoboken, 1804.
See screw-propeller, page 2071, Fig. 4747.
Twin-screws are used also upon some of the Winan's cigarsteamers, the thir
60°, and the upper of about 80°, with the axis, the concavity facing the wind.
The breadth of the sails is usually about 1/5 or 1/6 of the length, which varies from 30 to 40 feet, and they are preferably widened toward their outer extremities.
Their maximum effect is attained when their outer ends revolve with about 2 1/2 times the velocity of the wind.
In 1772 Andrew Meikle, of Scotland, invented a plan for automatically adjusting the area of the sails to the force of the wind; and in 1804, By water of Nottingham, England, patented a method of rolling up the sails to adjust them in like manner, by means of a weighted lever, which was caused to operate gears, connected by cords to cylinders, on which the sails were wound.
More recent devices of this kind generally aim to effect this adjustment by altering the angle at which the sails are presented to the wind.
In some cases the axis on which the sails rotate is caused to fall in the line of direction of the wind by means o