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436 
THRASHING 
Mr. Meikle’s barley-mill; and in a few minutes 
after it began to be tried, it was torn to pieces ;— 
and the like fate befel a machine of full size 
which Sir Francis erected, a few years after- 
wards, for one of his tenants. 
“Mr. Meikle,” says Sir John Sinclair, “ was at 
this time induced to try if the work of thrashing 
corn could be accomplished upon a principle, 
which had not been previously acted upon by 
any other person. It is evident, that the power 
required to thrash corn in a perfect manner, or 
even in any quantity, must be considerable; for 
no machine is capable of performing this opera- 
tion correctly, if the scutchers do not move with 
a velocity of 2,500 feet in a minute. He there- 
fore resolved to attempt thrashing by means of 
a cylinder or drum, placed in a horizontal posi- 
tion, upon the circumference of which thrashers 
or scutchers should be fixed, in such a manner, 
as to endure the necessary motion; being quite 
satisfied, that corn, without velocity in the 
thrashing-drum, could not be detached from the 
straw in a satisfactory manner. The attempt 
was made, and the success completely answered 
his expectations and wishes. The first thrash- 
ing-machine erected by Mr. Meikle, was on ac- 
count of Mr. Stein, at Kilbagie, in Clackmannan- 
shire, about the year 1786; and a certain proof 
that such a machine was then altogether un- 
known, may be inferred from the agreement 
about this erection, it being therein stipulated, 
that Mr. Stein was to furnish the materials, and 
if the machine did not answer the intended pur- 
pose, Mr. Meikle was to receive no payment for 
the workmanship. This thrashing-machine being 
successful, another, on the same principles, was 
erected for Mr. Selby, at Middleton, in Northum- 
berland, which was immediately copied and imi- 
tated by several mill-wrights in that county; 
one of whom had the singular modesty to claim 
the invention, because he had previously made a 
model of Mr. Alderton’s machine, which was 
constructed on quite different principles. The 
utility of Mr. Meikle’s machine being satisfac- 
torily ascertained, a patent for the invention was 
obtained, securing its benefits to him and his 
heirs for the period of 14 years. It is a singular 
circumstance, that though this patent was ob- 
tained at considerable expence, it was not acted 
upon. When ten years of the patent were ex- 
pired, some of Mr. Meikle’s friends stood forward, 
and endeavoured to put it in force; but there 
was then such a number of erections by others, 
that the design could not be executed, without 
risking an expence, which would not have been 
compensated by any profits that could have been 
gained during the unexpired years of the patent. 
Since the invention of this valuable machine, va- 
rious improvements have been introduced, not 
only by the inventor, but also by others, all 
tending to simplify the labour, and to augment 
the quantity of work performed. When first 
erected, though the corn was equally well sepa- 
MACHINES. 
rated from-the straw, yet, as the whole of the 
corn, straw, and chaff, were indiscriminately 
thrown into a heap, the work could only be con- 
sidered as half executed. But; by the addition 
of shakers and fanners, all driven by the same 
power, the different processes of thrashing, shak- 
ing, and winnowing, are now all performed at 
once, and the grain immediately prepared for 
the market.” 
The modern Scotch thrashing-machine, con- 
structed on the principle of Meikle’s, and com- 
prising all the most important improvements up to 
the year 1839, is represented in Plate LXI. Fig. 
1 is an elevation, and /7y. 2 a ground plan; and 
the same letters refer in both figures to the cor- 
responding parts. AA represent the position and 
arrangement of the feeding rollers, B the drum, 
C the first rake, D the second rake, E the apron, 
FF the screen, GG the hopper, HH the first and 
second fanners, I the connecting spur-wheel, K 
the elevators, LU, &c., the framing of the mill, 
M the rake-chain, NN the fanner-rope, O the 
roller-chain, P the upper pulley, for elevators of 
‘shorts,’ Q the upper pulley for elevators of se- 
cond fanners and hummellers.—The drum is the 
most important part; and in giving it motion, a 
very great portion of the moving power is ex- 
pended. It being the standard for the dimen- 
sions and the velocity of the other parts, its 
construction and velocity are of much impor- 
tance. To thrash clean, the drum requires to 
move with a velocity of 320 revolutions per 
minute, where its diameter is 39 inches, this 
diameter being, after numerous experiments, 
considered the most effective. 
the drum, that has been in like manner deter- 
mined from a train of experiments, is 3 feet 6 
inches, for a machine of six-horse power. From 
the velocity at which the drum moves, and the 
force with which the beaters strike the straw, it 
requires to be made of materials at once light 
and durable. These consist of an axle of mallea- 
ble iron, with arms of the best hard wood, fixed 
in malleable iron flanges. The best covering for 
the drum is sheet iron, No. 24, being both clean 
and light. The beaters are made of the best 
hardwood, 2 inches thick, and 3} inches deep, 
faced with malleable iron, steeled, and gths of 
an inch thick on the striking edge. To prevent 
the straw from winding about the axle of the 
drum, the frame is exactly fitted to its length, 
so as not to have a void of more than one-half 
inch at each end of the drum.—The feeding rol- 
lers are about one inch longer than the drum; 
and they should have weight sufficient to pre- 
vent the beaters from pulling the corn faster 
through than the rollers pass it, and should pre- 
sent the corn to the beaters as directly as possi- 
ble. These objects are attained by solid cast-iron | 
rollers of 4 inches diameter. Some corn from its 
nature, and others from its state, requiring a 
greater number of strokes to thrash it than 
others, the feeding rollers are fitted up so as to 
The length of | 
