Ward’s Steam-Engine. 10r 
as you lessen the time, you increase the velocity, and, of 
course, the momentum. In the lever oe this transfer 
takes place four times, during every revolution ; that is, the 
beam is accelerated and retarded, during the first half of the 
revolution, and again accelerated and retarded, during the 
other half. In my engine, the transfer takes place but twice 
in the whole revolution ; that is, the cylinder is accelerated 
during one half, and retarded during the other. If, then, we 
suppose the revolution, i in each case, to be performed i in the 
same time, it follows, that two transfers of momentum 
in the lever engine, inthe same time that one only takes place 
in mine ; and that the velocity — Liat and strain, 
at each transfer, are twice as great mine. The strain 
is also greater from two oth first, because 
the weight of the cylinder, which ae body accelerated 
and retarded in my engine, is not so heavy as the beam; and 
secondly, because it is placed nearer the centre of motion 
than the parts of the beam.—2. As the steam contained in 
the tubes, extending from the cocks to the ends of the cyl- 
inder, is necessarily lost at each revolution, the shorter these 
tubes are, the better ; and the cocks being placed, in my 
engine, on the sides of the cylinder, aoe aggregate length of 
these tubes is no greater than the length of the cylinder it- 
self.—3. The friction is er “diminished both because 
fewer pieces of ma : ed reno i 
action and reaction are stained by idgeons, wh 
revolve the same way,—except those of the cross- cross-piece | at 
the head of the sition 268, Shick fave a vibrate? iaoliog 
4, There being less use of steam, of come less fisel will be vel willbe 
necessary ; and this is not only a saving of expense, 
room also, and freight; since it is well known, that the bulk 
and weight of the wood consumed, in the common steam- 
boats, cause a material nr ite on the profits of those es- 
tablishments.—5. Many of the old pieces of machinery be 
ing got rid of, my engine is less bulky, a great deal lighter, 
much less expensive, and ey durable than any other.— 
6. There is a very great saving of room in placing the en- 
gine within the water-wheel.—7. If there be a water-whee] 
y ty, by 
merely es the wanice velxe belonging to the one wheel 
