IMPROVEMENTS IN HYDRAULIC ENGINES. 



wvn's engine, and another of a method of caufing the Schem- 

 nitz to raife water above the level of the prime refervoir, to- 

 gether with a comparative view of the advantages of both 

 engines and their powers. 

 Concife cxpla- After a perufal of my former Paper on the Schemnitz en- 



Schemnitf en- ginC ' ^ IV ' U4 '^ * mCre inf P eaion of the % ure g iven here 

 ginc. (Plate I.) will be fufficient to fliew the manner in which this 



now propofed will operate. The moving power is the pref- 

 fure of the column of water from the refervoir R, (Fig. 1.) to 

 D in the lower air chamber A, which forces the air contained in 

 it into the chamber B, which air fo comprefied in B will impel 

 the water contained in it upwards through the pipe to a 

 height, and in a quantity proportionate to the relative height 

 of the column of water contained in the pipe R D, compared 

 with that contained in SB, or iuppofing the length of R D 

 given, the greater the length of the pipe S B is, (fo as not 

 to exceed R D,) the lefs will be the quantity of water deli- 

 vered at S, and vice verja. 

 Mr. Goodwyn's In the draft of Mr. Goodwyn's engine, Fig. 2. I have en- 

 *: ngl " e 5 !: on " deavoured to exhibit it as it fliould be if executed on a large 



ftructed for ° 



heavy work, fcale, and made all the pipes detached from each other, be- 

 and made to ope- cau f e though the plan of making one pipe pafs through an- 

 tendance. other and through the refervoirs, made ufe of in Mr. Good- 



wyn's model, is very convenient and neat in an apparatus 

 that may be placed on a table, yet it would be found to pro- 

 duce an unneceflary trouble, complication and difficulty of 

 repair in a large engine. The method (hewn in this draft of 

 caufing the engine to work without attendance, is the fame 

 as for the Schemnitz, and caufes the cocks G and H to open 

 at intervals, (which may be regulated at pleafure by the hand 

 cock I, letting the water flow more or lefs quick into the {y- 

 phon veflel E,) while at the fame time it clofes the cock at D, 

 and vicevcrjb. Self-moving valves are placed at the deliver- 

 ing pipes of the chambers C and B, and alfo at the air vent 

 of A, becaufe wherever they can be ufed they are preferable 

 to cocks, or valves ufed by external power ; ibme doubt may 

 arife, whether there fliould not be a palTage for the air let at 

 intervals into A, as well as one for it to efcape : but as great 

 quantities of air are contained in water, which the mode of 

 working of this engine will particularly tend to feparate from 

 it, I think it would be needlef and that the felf-moving 



valve 



