Notice of the Revolving Steam Engine. 145 



state, it being an admitted point, that the laws of the United 

 States are the paramount authority. Wherefore, patented 

 operations cannot be legally excluded. 



But Mr. Ward's apprehension is shewn to be unfounded, 

 by the performance of an engine of this kind during the last 

 three years, at a manufactory near Boston, even without this 

 precaution. 



Unwilling to occupy your pages with this familiar sub- 

 ject, I will only add, that it appears to have been the ob- 

 ject of Mr. Watt's experiments, to avoid the use of the crank 

 as involving the necessity of a fly-wheel, to which motion 

 must be given, at some expense of power, at every stroke. 

 If I am not mistaken, the double revolving engine, is ef- 

 fectively a rotary engine. It has no dead-point, and re- 

 quires no fly-wheel ; and it is so far different from those 

 reciprocating engines, which work with a heavy beam, that 

 the indispensable weight of the machine, has a degree of 

 momentum, that contributes to the steadiness of its opera- 

 tion. It appears to me, that to produce the same effect, 

 Mr. Ward must place two cylinders in each water wheel at 

 right angles. 



Since this occasion of addressing you occurs, permit me to 

 avail myself of the opportunity, to describe a small improve- 

 ment in the steam boiler, put in practice in this boat, to com- 

 bine strength with horizontal extension, in order to offer a 

 great proportional surface to the fire, and yet carry a light 

 load of water. 



I took the material, that would have made a boiler of 

 eight feet diameter, seventeen feet long, and formed seven 

 cyHndrical vessels : having conical heads, terminating in 

 flanches to which are attached, a cross connecting pipe, 

 thus making one boiler of them. The steam rises from the 

 centre of each into a common chamber, on which the safe- 

 ty valve, and throttle valve are situated. The support is 

 from four semicircular irons, or arches, from which suspend- 

 ing irons descend, &;c. The spaces between, are filled with 

 brick. The flue passes under them above deck ; its sides 

 and floor are formed of water vessels, kept full by the sur- 

 plusage of the supply pump, for which they prepare the 

 water ; under the grate, however, there is an air chamber 

 formed of two thicknesses of sheet copper,the space between 

 them being also supplied with water, this descends a few 



Vol. V,— No. 1. 19 



