Steam-Engine—Physics, §¢. i161 
In the United States, instances are not wanting of the suc- 
cessful operation of high steam; of which the engine at the 
mint is a conspicuous example. There can, indeed, be no 
good reason why this great power should not be employed to 
an extent within the limits of safety, if more economical and 
convenient. If boilers can bear (as they are usually made of 
iron) 500 pounds, there can be no danger in using them with 
fifty ; and this gives an increase of power, with a condenser, 
fourfold, or makes a ten horse power forty. The economy, 
therefore, of high steam, hardly admits of a question. It 
seems unphilosophical to neglect a power so great, merely be- 
cause it is so. 
Mr. Watt was desirous of an improvement by which to 
obtain a direct rotatory motion. His experiments, resembling 
those of Curtis, at New-York, were not found permanently 
practicable, 
It was probably perceived to be a great object to get rid of 
4 reciprocating movement of large masses, on the well-known 
mechanical principle, that it consumes power to check mo- 
mentum, as well as to give it—to drag an inert mass into 
motion rapidly, in opposite directions. And in engines for 
navigation this is more disadvantageous than for land uses, as 
the foundation of the engine cannot be perfectly substantial. 
An engine, therefore, that possesses the cylinder and other 
members of Watt’s engine, working with or without a con- 
denser, at pleasure—having a rotatory movement—requiring no 
ponderous balance-wheel—adapted to high steam—attended by 
nO inconvenience from the rapidity of its stroke or move- 
ment—having no inert mass of machinery to move recipro- 
cally—more powerful, proportionately, from its using steam 
“Sstrong as that in the boiler—of a simple and durable con- 
Struction, and by a combination of two similar machines at- 
tached to the same common intermediate axis, operating so as 
‘give nearly an equal power at every movement of its opera- 
tion, seems to combine every thing desirable in an engine for 
the purposes of navigation. Such appears to be the revolving 
“ngine invented by Mr. Morey. : 
x Be a1 
OL. L....No, 
