210 HYDRAULICS. 



time it opens the injection-cock. The rising-pipe 

 being still full of water, a stream of cold water 

 proceeds through the pipe e, and enters the re- 

 ceiver in a shower. This instantly condenses the 

 steam in the receiver, and produces a vacuum as 

 before ; in consequence of which, the water from 

 the well is again forced up by the external pres- 

 sure of the atmosphere, and the receiver is again 

 filled with water. The regulator is then turned, 

 which shuts the injection-cock and opens the 

 steam-cock, permitting the steam from the boiler 

 to press upon the water, and again force it up the 

 rising-pipe. This operation of rilling the receiver 

 with water by means of a vacuum produced in it, 

 and forcing it up the rising-pipe by the pressure 

 of the steam from the boiler, is constantly re- 

 peated, by merely turning the regulator, which 

 shuts and opens the steam-cocks and injection- 

 cocks alternately. 



This construction of this steam-engine is ex- 

 tremely simple, and it might, perhaps, be success- 

 fully applied for some purposes. But it has several 

 defects. The action of the direct steam on any 

 definite surface, as, for example, a square inch, is 

 accurately equal to the re-action of the water 

 which is forced up ; consequently, Savary's engine 

 will require steam more elastic than the air of the 

 atmosphere, in every case except where the water 

 is raised no higher than it can be by the vacuum 

 that is produced, and the pressure of the atmo- 

 sphere. When the water is forced up through the 

 rising-pipe, every square inch of the boiler must 

 sustain a pressure equal to a column of water an 

 inch square, and of the height of the pipe above 

 the boiler. This, therefore, requires very strong 

 vessels, and several accidents happened by their 



