473 
Steam Engines* 
it twenty waggons, each containing three tons of coal, at the tate 
of four miles an hour. I find, that steam applied to draught car^ 
riages, has been used for some years in England, and the practice 
is extending. 
It is with very sincei‘e satisfaction, I announce, that several gen^ 
tlemen of considerable mechanical abilities, in our own country, 
are now turning their attention to the improvement and construe^ 
tion of steam engines. Several drawings have been sent to me for 
opinion and publication, but at present, I can do no more than 
briefly notice the principles adopted. 
In Mr. Fulton's engines, the method of packing the piston, 
of preserving the prependicularity of the stroke, of communicate 
ing the rotatory motion, and the form and dimensions of the un- 
wieldy working beam, have been improved, since my time of obser«- 
vation. 
Mr. French^ of New York state, is also constructing engines, 
with some improvements on Boulton and Watt’s, as I have heard, 
but I do not know exactly what the alterations are. 
Mr. Oliver Evanses establishments in Philadelphia and at Pitts- 
burgh, have early and greatly contributed to bring steam engines 
into use, but I do not accurately understand the point on which his 
claim to a patent right, is meant to rest. If I had the precise in- 
vention explicitly described, I should be glad to give it that cur- 
rency, to which its novelty may entitle it. 
Mr. Rodman^ oi Washington, South Carolina, has sent me the 
drawing of an atmospneric engine, working with two cylinders, 
which appears to possess considerable merit, as to the simplicity 
and consequent cheapness of the machinery. I do not remark any 
contrivance to preserve the perpendicularity of the stroke. The 
construction and situation of his valve, I understand, is much like 
the method adopted by Mr. French: but about this I am not able 
to speak with accuracy. 
Mr. Ogden^ of Pittsburgh, is also engaged on a steam engine, 
with two cylinders contiguous to each other. He proposes work- 
ing his steam of whatever density, in two cylinders, to be stopt off 
at any point. If at one half, the instant one cylinder is half filled, 
its steam valve is closed, and the steam valve of the other is open- 
ed. On the first pistons arriving at the end of its stroke, that of 
the other cylinder will have performed half a one. Its steam valve 
will then be closed, and that of the first again opened, as well as 
its opposite condensing valve ; in this manner the mqtIot\ will 
