WATKU 1'INU'ULSION. 379 



moderate degree of velocity in the direction of the course of the 

 vessel, and ejected with great force and speed in a direction 

 opposite to the course of the vessel through the same orifice, 

 reduced to about a quarter of the area by means of a. valve 

 opening as the water enters, and partially shutting as the water 

 is ejected ; and thus I propel the vessel with great force, derived 

 from the recoil of the water set into rapid motion in a direction 

 opposite to the course of the vessel, the rapidity of the jet of 

 water to be at least equal to double the required speed of the 

 vessel to be navigated. 



" And I further declare, that by preference I effect the pur- 

 pose of receiving and of ejecting the water, and of deriving a 

 motive force from its recoil, by means of a large vertical cylinder 

 of cast iron or other metal, closed at both ends, in which a piston 

 is forced up and down by a piston-rod sliding through a stuffing 

 box in the lid, which piston-rod receives its motive force from 

 a steam-engine ; and I fix a tube into the after side of this 

 cylinder, near the bottom, in communication with the space 

 below the piston, which tube leads through the stern of the 

 vessel, as low down as practicable, and opens on one side of the 

 rudder ; and I fix another tube into the after side of this cylinder, 

 near the top, in communication with the space above the piston, 

 which tube also leads through the stern of the vessel, as low 

 down as practicable, but opens out on the other side of the 

 rudder ; and I place in the mouth of each of these tubes a valve 

 opening inwards, to allow the water free entrance, equal to the 

 bore of the tube, and partially shutting when the water is 

 ejected, so as to reduce the opening through the stern to about 

 one-fourth of the area of the tube. 



" And I do hereby further declare, that the nature of my said 

 invention, as regards the improvement in the application of 

 steam-power to locomotion, consists in the application of such a 

 boiler, together with the expanding apparatus as aforesaid, to 

 locomotive engines, whereby a diminished weight of boiler and 

 quantity of water and fuel is obtained; and in further com- 

 pliance with the said proviso, I, the said Bichard Trevithick, do 

 hereby describe the manner in which my said invention is to be 

 performed, by the following description of its various parts in 



