Steam Engine, S7S 
The wedges c, S, Fig. 1. Plate IV. thus applied^ would 
be an improvement, for want of which a lever of this sort 
in the hands of a negligent engineman had one of its 
joggles forced olF, the shoulder of the tennon, which was 
morticed into the arch, not being a joint by the eighth of 
an inch, or more ; but when it met with the arch it went 
no further, and continued to work for many years under a 
great load, and much to its disadvantage in other respectSo 
The length of this lever was 21 feet, the scantles were 
12 inches by 6 ; height of the whole when put together 
SO inches, and leverage on the gudgeon as 4 to 3. This 
last circumstance operated much against its construction, 
by giving additional force against the joggle at that endj, 
but had it been framed six inches higher, I doubt not but 
it would have stood to this day under all its disadvantages. 
The sum of the scantles is 18 by 12, area of the sec- 
tion 216 inches, column of water in four lifts 4800 lbs. 
with 440 fathoms of rods, (pump rods) which with the 
appendages on the other end, added to the power neces- 
sary to overcome the resistance, amount to about seven 
tons. 
But a much simpler, and in some respects a more 
advantageous mode of framing is shewn at Fig. 2, and 
may be constructed with or without arches. This, with 
little variation, is the invention of a Dutch gentleman, 
and was applied to the load of a 52 inch cylinder (an at- 
mospherical engine) set up with advantages, which in 
point of workmanship at that time was perhaps not equal- 
led, and therefore may be said to have been fairly tried. 
This engine was calculated to raise 60,000 gallons per 
minute, and the scantles were 18 by 12, and 2 by 
8, and where such timber can be had, it is hardly to be 
expected to have a lever with greater advantages than this 
for a single stroke, and where a double stroke is required 
it may be doubled for that purpose, retaining all its princi^*. 
VoL IL 3 B 
