1823.]} 
pose, so that one of cach set of larger 
friction-rollers (which stand on each 
side of the middle ring) will work upon 
one outer circle, and the other upon the 
other outer circle ; and part of each outer 
roller, as it revolves round, wifi always 
be in the groove between the inner cir- 
cles after mentioned. The patentees 
then make a number of such smaller 
friction-rollers of the same materials as 
the larger friction-rollers, equal to the 
number of the larger friction-rollers, and 
unite them, so that the centre may be 
common to both, and that they may 
compose one friction-roller with differ- 
ent diameters, the spindles on the mid- 
dle ring running through both. If the 
calculation be made beforehand, the two 
parts of the friction-roller may be made 
in one piece, and this is the best way. 
They then make of steel or iron case-har- 
dened, or other strong material, the two 
smaller or inner circles of the diameter 
(calculated to their outer edges) found 
as above mentioned, to be screwed on 
to a circle of wood (turned solid, or com- 
posed of felleys), leaving a groove or 
space between such inner circles, in the 
Same manner as between the outer cir- 
cles. One of these inner circles is pla- 
ced so, that the smaller pheriphery of 
all the friction-rollers, which are on one 
side of the middle ring, touch its circum- 
ference, and the other the same on the 
other side of ihe middle ring; and the 
inner circles are then screwed on to the 
wood. Then, if the inner circle were 
set in motion, the smaller pheriphery of 
the friction-rollers would revolve on it 
in the same time as the larger periphery 
of the friction-roller, on the outer circles. 
The smaller pheriphery of the friction- 
Proceeding's of Public Societies. 
55 
rollers is not grooved, but flat, for the 
convenience of putting the machine to- 
gether. The inner circles do not rest on 
or touch that part of the friction-roller 
which projects beyond its smaller diame- 
ter, but are kept off from it by baving 
at the bottom of the lesser friction-roller, 
where it joins the larger friction-roller, a 
small shoulder or circular projection 
which the inner circle touches, and by 
which all lateral friction between the 
smaller or inner cirele and the side of 
what for explanation is called the larger 
friction-roller is prevented, The appli- 
cation of the machinery, when thus 
completed, must vary according to the 
purposes for which itis used. For car- 
riages there are several ways of using it; 
round the wood in which the outer cir- 
cle is fixed, a common tire may be put. 
‘The inner circle may be bolted or other= 
wise fastened on to the carriage if springs 
are required ; but, if they are not required, 
it may be bolted or fastened on to the body 
of the carriage. An axle running through 
the carriage and connecting the two 
wheels is not absolutely requisite, provi- 
ded the bolts or other fastenings are suffi- 
ciently. strong; but we apprehend it would 
be better, for the sake of strength and du- 
rability, to use a square axle; or the outer 
circle may be fastened to the side of or un« 
derneath the carriage, and a revolving 
axle run through the inner circle into a 
common carriage-wheel; or the whole ma- 
chinery may be put into the box or 
nave of a common wheel. When used 
for carriages, or any purpose which 
would expose the machinery to dust or ° 
other obstructions, a plate of iron or 
other sufficient covering should be used 
to enclose the parts.x—Repertory. 
PROCEEDINGS OF PUBLIC SOCIETIES. 
i 
SOCIETY for the IMPROVEMENT Of PRISON 
DISCIPLINE. 
(With an Engraving.) 
Y favour of the Committee of the 
Society for the Improvement of 
Prison Discipline, we are enabled to in- 
troduce to our readers a view of the 
famous 'I'read-mill in use at the House of 
Correction at Brixton, in Surrey, and 
lately introduced into other similar es- 
tablisbments. As manis the creature of 
habit, it is palpable that nothing can be 
more desirable than that persons faicly 
tried and condemned to punishments, 
Justly proportioned to their obduracy 
and turpitude, should be employed 
while in prison, or habits of idleness wil} 
be engendered, instead of being cor- 
reeted. It has been a problem of great 
difficulty to find such employment as 
adapted itself to uninstructed muscular 
exertion, without entangling itself with 
the details of produce and sale; but, at 
length, Mr. Cubitt, of Ipswich, has con- 
trived a mill to grind corn and raise 
water for the prison use, to be worked 
by treadles, in performing whieh no pre- 
vious instruction is requisite. Benevo- 
lence can object nothing to the use of 
such a machine, provided it is not em- 
ployed 
