MILLS. 
contrivance was nothing more than causing 
them to roll up lengtliwise, by means of 
small wheels, or ratchets, placed near tlie 
axis, and acted upon by it in its revolution. 
Mills, horizontal wind, have likewise 
been tried, but they are both troublesome 
to manage and deficient in power : on the 
other hand, tliey are far safer, and cheaper 
in their construction than the vertical kind. 
Tlie simplest mode of constructing a wind- 
mill is with a spiral sail, passing round a 
centre pole, tapering towards the summit, 
and spreading to a great width at the base. 
This certainly has not very great powers, 
but acts with great uniformity, and requires 
no attendance, since it matters not from 
what quarter the wind blows. We consider 
this machine to be very well calculated for 
raising water from fens, &c. both on account 
of its cheapness and its safety, even in tlie 
most exposed situations. The pole, or axis, 
to which the sail is fastened all the way up, 
being perpendicular, and every part pre- 
sented to the wind giving it a tendency to 
rotation, while the main part being below, 
insures a steady action, and that absence of 
violent friction which cannot be effected in 
a vertical mill, or in any machine where the 
greater part of the power is derived from 
the extremities of long arms, or vanes. See 
Windmill. 
Mills, horse and hand, are usually upon a 
small construction, rarely calculated to pro- 
duce any considerable effect, and more ap- 
propriate to domestic purposes of Inferior 
consideration. These machines, as their 
names imply, derive their action from ani- 
mal force, which is unquestionably the 
dearest, most irregular, and least efficient, of 
all the powershitherto applied to mechanism. 
In horse-mills, one, two, or more horses, 
or other cattle, are made either to draw, 
or push before them, levers, which project 
from a centre shaft, bearing the great hori- 
zontal wheel that gives motion to the more 
remote parts, and which act with more or 
less effect, according to the length of the 
levers, and the number of cattle employed. 
For threshing, drawing water, grinding, po- 
lishing, &c. such a power answers as a sub- 
stitute where water is not at command. But, 
owing to the inequality of pace, and to the 
great propensity all animals have to lean 
towards the centre (in lieu of moving with 
freedom along the given circle of perambu- 
lation), all machines worked by cattle in- 
variably become speedily deranged, and are 
encumbered with an excess of friction. 
Hand-mills labour under a similar inconve- 
nience ; though such as are regulated by 
fly-wheels, which occasion a great accumu- 
lation of force, and at the same time dispose 
to a degree of regularity in its action, are 
both more efficient and more durable. Of 
these we have numbers, such as chaff-cutting 
machines, grind-stones, &c ; indeed, the 
mangle may be included among this class. 
In several countries the whole of the flour, 
meal, &c. used by the natives, are produced 
by means of hand-mills ; our legislature, 
however, considering these as drawbacks on 
the livelihood of a very numerous class, has 
prohibited their use, under very heavy 
penalties. In many parts of Scotland the 
tenants are generally thirled, i. e. invariably 
obliged to send whatever corn they wish to 
grind to some particular mill ; any deviation 
is actionable. This was at one time, per- 
haps, necessary, for the encouragement of 
millers, when they first introduced water 
machinery into that kingdom; at present it 
operates not only as an inconvenience, but, 
in many instances, as a hardship, amounting 
nearly to a prohibition. The evil, however, 
sometimes carries its own remedy, for the 
tenants sell their corn to the owner of some 
other neighbouring mill; and, when it is 
ground, buy the flour it produced : thus they 
evade the thirling, which binds only to the 
grinding of what they do not dispose of. 
Mills, bark, are most frequently worked 
by cattle, and perform their office by means 
either of large beams called beetles, which 
being lifted in successive order fall into 
cavities wherein the bark, previously dres- 
sed in a proper manner, is placed, and 
pounds it to a sufficient degree of fineness 
to answer the tanner’s purpose. Madder, 
and many other articles used in various 
trades, are also broken in the same manner. 
Paper is made from rags, which being dust- 
ed in sieves, &c. and soaked, are macerated 
in a mill, which tears the several fibres 
apart, and reduces the whole to a fine 
pulp. 
Mills, coffee and pepper, are too well 
known to require detail; we were not a 
lit(Ie surprised to find the ordinary machi- 
nei'y of this class, when extended to a very 
large scale, obtain a patent for the grinding 
of bark. 
Mills, oil, are very simple in their con- 
struction ; they being nearly the same as 
cyder-mills ; consisting of troughs wherein 
the seed is broken by the passage of im- 
mense cylinders, or cones, of iron or stone, 
and afterwards put into presses for the pur- 
pose of forcing the oil from the residuum ; 
