4^*5 'Rotatory Hydr-aulic Engine. 



The theory, according to which the preceding folution has been propofed, fuppofes the 

 eleiSric fluid ^ Jlng/e fluid ; but it is not neceflary that it (hould be conceived to be abfo- 

 ]MidYj!mpk. We know, for inftance, that atmofpheric air is a combination of at lead 

 two diftincSl fluids ; and yet explain the phsenomena of the barometer, air pump, aftd con- 

 denfer, as depending merely on its prefence or abfence, without any reference to the com- 

 pofition of its nature. In the fame manner fome eleftric phxnomena may be juftly ex- 

 plained by confidering them as the efl'e£ls of the different diftribution of the fame fluid ; 

 whilft its phofphoric fmell, its power of changing blue vegetable colours to red, and its 

 combullion may poflibly be derived from its decompofition. 



VI. 



Defcription of a new Rotatory Engine for raifing Water, and for other Purpofes: By a 



Correfpondent. 



To Mr. NICHOLSON. 

 SIR, 



I 



SUBMIT to your judgment, and (hall be much gratified by your opinion on the en- 

 gine of which I fend you the inclofed drawing. If you think it may be intitled to a place 

 in your colledlion, cither as an apparatus, or as affording fome hints to the improvement 

 of hydraulics, the whole of my views refpefting it will be anfwered. I will confefs to you, 

 that I have not conftrufted it upon a fcale of a£lual work, and am well aware how 

 many fubordinatc points of organization require to be fettled, before any mechanical con- 

 trivance can obtain its beft and moft effe£live form : but as it has already been the fubje£l 

 of a confiderable degree of meditation, I have ventured to offer It to you in its prefeuf 

 ftate. 



I am, Sir, 



Your obliged Servant, 



Lfftdortf Dec. 14, 1800. O. B. 



DESCRIPTION. 



In Plate XX. the upper figure reprefents an horizontal feftion of the main part of the 

 engine, and the lower figure fliews the fame engine, as it would appear to an obferver 

 viewing it at right angles to the former direQion of fight : the fame letters in both denoting 

 the fame parts. A A reprefents an elliptical veffel of wood, or rather of metal, having, 

 its top and bottom flat, and joined to the fides by flanches or borders. The fides are up- 

 right, and may be of any height according to the intended capacity. In this veffel revolves 

 the cylinder B, B, having the fame axis, an4 touching the internal circumference at two 



oppofitc 



