378 . SUPERHEATING CYLINDER, 



tire, and within the circular row of upright pipes of the boiler 

 hereinbefore described ; and I form my dry pipes in pairs, each 

 pair constituting the figure that is well understood by the term 

 inverted syphon ; and I unite several of these syphons together 

 by short bent pipes at the top, so as to constitute one long zig- 

 zag pipe, through which the steam must successively pass down 

 and up the alternate legs of each syphon with great velocity, 

 necessary for the rapid absorption of heat in its passage from 

 the boiler to the working cylinder of the engine, the working 

 cock, valves, or slide of which being united by a pipe of com- 

 munication with that leg which is last in the succession of 

 syphons ; and I unite the first in succession of these inverted 

 syphons with the upper tubular ring of the boiler by means of 

 a bent pipe, in which a throttle-valve or cock is placed in order 

 to limit the supply of steam, that it may have space in the dry 

 pipes and working cylinder to expand in proportion as it receives 

 additional heat; and J fix a safety-valve in communication with 

 the boiler, and another in communication with the dry pipes ; 

 and I place around outside the boiler, at a small distance from 

 the upright pipes, two cylindrical casings, one within the other, 

 and fill up the space between the two casings with sand, ashes, 

 or other material which conducts heat but slowly ; and I close 

 up the upper end of the casings over the boiler and the dry 

 pipes with a covering in the form of a dome, and out of this 

 enclosure I make the flue to pass to and around the working 

 cylinder of the engine, whence the flue carries the smoke and 

 little remaining heat away in any convenient manner; and 

 I make my boiler-pipes, rings, and casings by preference of 

 iron or copper, and my dry pipes of copper or other strong- 

 metal not liable to rapid oxidation by heat when in contact 

 with steam ; and I supply my boiler with water by means of a 

 forcing pump, so adjusted as to keep the water of the proper 

 height. 



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

 invention, as regards the improvements in the application of 

 steam-power to navigation, consists in the drawing of water into a 

 receptacle placed near within the stern of the navigable vessel, 

 which water is drawn in through an orifice in the stern with a 



