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Descriptuyii of a Design for a Rotatory Steam-Engine. By 

 Mr James White. With a Plate. Communicated by 

 the Author. 



xjLfter completing my design, I feel a degree of diffidence in 

 submitting it to public notice. Nearly two hundred years have 

 past away since the first attempt to produce a rotatory motion 

 in the first instance by steam, such a period of time having in- 

 volved itself betwixt the original and the present ; and the men 

 of genius, both in our own country and abroad, that have la- 

 boured to effect this object, and the universal failure of all their 

 designs, when compared with the present perfect state of the 

 Reciprocating Engine, has absolutely marked the name of Ro- 

 tatory in Steam-engines as something like a wild scheme, and 

 left us but Httle hope that we shall ever be able to wipe that 

 stain away. 



Those who are well acquainted with the principles of steam, 

 and the different schemes that have been devised for a rotatory 

 steam-engine, are aware, that the friction occasioned from an 

 unequal pressure of steam on the revolving cylinder, has been 

 the great obstacle which stood in the way of success. That 

 such difficulties no longer exist, can be plainly shown in my de- 

 sign. First, let it be understood that the engine consists of one 

 large outside cylinder, divided by plates into three divisions ; 

 the mid division being in length equal to the other two. In 

 each of these divisions, smaller cylinders are concentrically 

 placed, called the revolving cylinders ; the difference betwixt 

 the inside diameter of the outer cylinder, and the outside dia- 

 meters of the inner ones, forms the steam-passage. Let A,, 

 Plate V. Fig. 1. represent one of the revolving cyhnders ; 

 then B, B, will be the steam-passage: if the steam from the 

 boiler enter by the steam-pipe s, and pass downwards, it will 

 get into the steam-passage B, B, through the valve J\ act on 

 the piston-plate P, which is fast to the revolving cylinder, and 

 force it round ; when it has nearly made a revolution, the qua- 

 drants on the piston-plate will come in contact with the valve, 

 but not before the piston-plate has passed the passage C, lead- 

 ing to the condenser ; consequently the pressure is removed 



