550 THE CENTURY, 



details. So indefinitely has the Marquis s claim 

 hitherto been stated, that it is always assumed, that while 

 using this early steam engine, he was quite unac 

 quainted with condensation 5 or, at least, with any 

 mode of employing it to produce a useful effect. On the 

 other hand, it is not only more rational to suppose that 

 he could not be otherwise than fully acquainted with it, 

 but that, having ascertained its various results, he 

 finally succeeded in employing condensation to produce a 

 vacuum for refilling his vessels, and for giving motion 

 to a force or piston. Indeed, we find in the foregoing 

 statement &quot; 6. A particular Magazine for Water, 

 according to the intended quantity or Height of Water.&quot; 

 A particular Magazine, one for a special purpose, for 

 which it was particular to have such a supply ; and for 

 size, form, and situation, it had reference &quot; to the quan 

 tity and height of water,&quot; for a small cistern would 

 supply sufficient water for condensation, but a larger 

 cistern would be required in proportion to more ex 

 tended service. Then, &quot; 7. An Aqueduct,&quot; might be 

 the vertical main pipe ; and u 8. A place for the original 

 fountain,&quot; peculiarly arranged reservoirs, with suitable 

 valves, floats, &c. 



Uniting his several descriptions, we readily make out 

 a construction of apparatus answering many of the 

 conditions he has stated, as shown in the engraving* on 

 the opposite page from a sectional drawing designed 

 by the author. 



* DESCRIPTION OF THE ENGRAVING. 



A, A Two cold water vessels, connected by 



B, B 1 the steam pipe, with 



C, the Boiler, set in 



1), the furnace. The cold water vessels A A , also are connected with 



E, the vertical water pipe by means of 



F, F , continuations of the same pipe conducted into and nearly touching the 

 bottom of each vessel A, A . 



G, G , are two water supply pipes, with valves a, a 1 , dipping into 



H, the well. It is obvious that by uniting these pipes, and placing the valves in 



