382 MALMNE AND LOCOMOTIVE ENGINES. 



the steam is forced to pass with great rapidity without being 

 permitted to come in direct contact with water, by which 

 arrangement the steam is made to absorb additional heat, and 

 at the same time allowed to expand itself into a greater 

 volume. 



"Secondly, placing the working cylinder of the engine within 

 such part of the flue or chimney as shall ensure the cylinder to 

 be kept hotter than the steam used in it, by which means the 

 expanding of the steam is still further promoted. 



"Thirdly, propelling a navigable vessel by the force of the 

 recoil produced from water received with a moderate degree of 

 velocity, into a receptacle near within the stern, in the direction 

 of the course of the vessel, and ejected with great velocity in a 

 direction opposite to that course, the velocity of the jet being 

 at least double the required speed of the vessel to be propelled, 

 provided always that the same be effected in manner herein- 

 before described. 



" Fourthly, applying a boiler combined with a steam expand- 

 ing apparatus, as before described, instead of a boiler alone, to 

 a locomotive engine, whereby the power of the steam is applied 

 after the steam has undergone the expanding process, and 

 whereby a diminution is effected in the weight of the boiler, 

 and in the weight and consumption of water and of fuel." 



The two great objects in this 1832 patent were su- 

 perheating steam in tubular boilers, and propelling 

 ships by forcing a stream of water from the stern at a 

 speed of at least double that of the vessel. Similar 

 ideas may be traced in his patent of 1815, where a 

 tubular boiler gave superheated steam, and in 1809 his 

 patent for propelling steamboats u consists of a tube of 

 considerable length disposed horizontally in the water, 

 and the stroke of rowing is made by means of a piston 

 with valves." 



An engine of 100-horse power was ordered in Shrop- 

 shire to be placed on board the Government ship to 

 test the value of those patents of 1831 and 1832. One 



