100 Ward's Steam-Engine. 
cirele of motion. The force BD, in this case, is resolvable 
into BH and HD. parallel and perpendicular respectively to 
the radius AD; and that part of it, which is exerted in the 
direction of the tangent, will be represented by 
two tangential, forces EB and HD, are to each oth- 
er inversely as their distances frori the common centre of 
motion A. For, in the two triangles, ACD and AFB, the 
angle at A is common ; and the angles AFB and ACD be- 
ing right angles, the remaining angles ABF and ADC are 
equal, and the two emi similar. Therefore, BF (or 
HD) : DC (or EB): : AB: AD. And inversely, HD : 
AB:: EB: AD. 
But, from the properties of the Lever, forces which are 
to each other inversely as their distances from the fulcrum, 
or common centre of motion, eswonees each other, and 
HD an 
produce an equilibrium. The two forces, 
therefore, would counteract: asic ther, or, which is the 
same thing, produce equal effects, — 
. ‘he er ror on this 
gine to ¢ e upon the larger < = LDM, from without 
its tence. when, of co the sweep of piston 
would be equal to the diameter: os dlie circle LDM ; and 
then comparing this engine with one on my plan, fixed at 
B, and with a sweep of piston, equal only to the diameter of 
the small circle BKZ. aking it for granted, that both en- 
gines would be of equal power, vit was easy to show, that the 
one on my plan would loose as much more power than the 
other, as the diameter of the large circle was greater than 
that of the less; but it was overlooked, that the two engines 
would consume steam and fuel exactly i in the same propor- 
tion,—that my engine would consume as much less steam 
and fuel as its ae of piston was less than that of the. 
other,—that, in a word, the power consumed by my — 
would be equal ony to AB » while that consumed by ‘th 
other would equal AD. — 
The advantages of my y engine over the Lever Cube 
may be enumerated as follows: 1. The alternate ark 
of momentum from the reciprocating mass to the fly-whee 
and vice versa, as above described, occasions a strain nee 
1088 | parts — the engine, which connect the —_- with 
he rotary parts ; and this strain increases 'y in pro- 
portion | as the time, in which it takes pince> ae ; for, 
