Ward’s Steam-Enewne. 93 
oO 
tardation, the whole of the momentum, which existed in 
the reciprocating mass, at the time of its greatest velocity, 
is gradually transferred to the fly-wheel : and, in like man- 
ner, during the acceleration, this same quantity of momen- 
tum is again transferred from the fly-wheel to the recipro- 
cating mass.* It is this gradual transference of all the mo- 
mentum of the reciprocating mass to the fly-wheel, and not 
the power of the steam “ dragging the mass in an opposite 
direction,’”—that ‘checks’? its motion, and causes it to 
stop. 
It seems to me, therefore, a work worse than nu- 
gatory, to waste ingenuity in devising modes of avoiding the 
reciprocating movement ; and it has, I believe, invariably 
‘happened, that men of genius, while striving to shun this 
phantom, have encountered or overlooked real difficulties, 
which, if not fatal, have proved so serious a disadvantage 
to their respective inventions, as to render them entirely 
useless m practice. If there be any exception to this re- 
mark, it must be in favour of the Revolving Engine, in- 
vented by Mr. Morey.» Much, however, as ‘his ingenious 
machine appeared, at first, to promise, I apprehend it 
will be found, upon a short trial, that he, too, has neglected 
to provide against substantial difficulties, while endeavour- 
ing to getrid of such as were merely imaginary. 
The great disadvantage in transferring momentum from 
a straight line to the circle, arises from the friction, which 
necessarily attends the operation. When, for instance, the 
piston-rod is made to play in whatare called parallel guides, 
and a connecting-rod, attached to the cross-piece of the 
slides, gives motion to the crank, there are but two points, 
in which the original direction at the power, and its direc- 
tion, as applied to the crank, coincide with one another. In 
all other points, the connecting-rod forms an angle with the 
guides ; and this angle varies, from the smallest, which the 
construction of the Engine will allow,—being greater, as 
the crank-piece is longer, dnd less, as you increase the 
length of the connecting rod. In all but two points, there- 
fore, the power reacts obliquely upon the guides; and, 
when the angle is the largest, the strain and friction are so 
* This is also the opinion of Oliver Evans Vid, ‘* Abortion of the Young 
Steam Engineer’s Guide ;’? published in 1815. 
