The Sun.
London, England, 1848-08-29 00:00:00

N 7 AUGUST 29, 1848.

[PRICE SD.

IM ?ROVEMENT IN PRINTING.
A ne iv printing machine has recently been produced
in Ame rica, the invention of Colonel Hoe, a partner in
:Lown engineering house in New York.' This
maLlaile sears quite novel in its working, and is called
by tie . Americans, " Hoe's Last Fast Press." The fol-
io wiet. Acieription of the working of the machine is
from t _Philadelphia Ledger :7

" TI ie .essential principle of difference betrreen this
last in% en. ,ion and all other kinds of presses or machines
hitherto led consists in the fact that while upon those
the typr x are locked up with quoins' and mallet
and rho it,.ng-stick,' in a chace, and laid flat upon a
bed' of *i •on, the surface of which is flat; with this one
the :Ype, ; are screwed up with a wrench, in what our
composit or c are pleased to denomine a turtle,' consti-
tuting bo bed and chace, and placed upon a large cy-
linder, fu as and a half feet in diameter, more or less,
which re r. iives upon its own axle within four other
smaller c) the fourth part the size of the, larger
one, thesE revolving also upon their own axles in an op-
posite dirt sclion.
"Each et e of these smaller cylinders receives from
its supply kg attendant the sheet of paper with which,
at every fo irth revolution, it meets the form or ' turtle'
of type as i comes round, and in passing, gives the im-
pression, t 1 instantly throws it out into the receiver's
hands, abc or below, according to the relative position
of the cyli at ier.
" Surrot in ding the large inner cylinder, to which the
form of t.y pe is attached, and between those giving the
impressiol , are placed the inking rollers, which spread
the ink up, n] the face of the type as it revolves under
them. Tf *re are two of these to each cylinder. The
inking fou stain is placed entirely underneath the ma-
chine, fro's% which the ink is constantly drawn by means
of a contin wally revolving small iron cylinder, forming
itself a pat .t of the fountain. From this the ink is taken
up by mean is of small rollers, with a small vibrating dis-
tributor, working in connection with them, and is con-
veyed to the surface of the large cylinder, the entire cir-
cumference- of which, except that section of it occupied
,hy„the form of typorperforms in its revolution the office
of both diltributer `and feeder to the eight inking'
rollers, from which latter the types receive their supply
direct.

" With two of the cylinders the white paper is fed in
above, and /he printed sheets are thrown out below, and
with the other two it is fed in below and thrown out
above. The room taken up by the machine, paper
boards, and ail included, is about sixteen feet in length,
and nine f:e;: .nigh by about five feet in breadth. The
types used ui.on it are the ordinary types hitherto used
upon the Lerver, which are made to assume a circular
form in the Ariake up ' by the use of bevelled column-
rules.

" For the attendance of this press ten persons are re-
quired—viz., a superintendent and an assistant, and four
to feed sheets in, and four to receive them as they come
out. This is the same number only that have been re-
quired to attend the two presses heretofore used in
printing the Ledger."
This machine, according to the Ledger, is capable of
throwing off' twelve thousand impressions an hour with
the same amount of labour as that bestowed on those in
ordinary use at the same office, and which are stated to
be the best that could be produced. The invention is
certainly one of great importance, and may be the
means of producing great changes in periodical lite-
rature.

POLYTECHNIC INSTITUTION.

Among the many attractions at this institution we
have been much gratified with a lecture, accompanied by
a working model, on the now hydro-carbon gas appa-
ratus, patented by Mr. Stephen White, which is ex-
hibited in the theatre, for the manufacture of gas from
water and common tar, or resin, &c.

The invention appears to be a very valuable one, and
is ably explained in its various points by Dr. Ryan.
The apparatus consists of three retorts placed in a stove,
two of which are filled with charcoal and thin pieces of
iron, and the other with iron chains hanging from a
centre bar. The two first retorts are for the decom-
position of water, which is regularly supplied
by means of a syphon-pipe passing through and into the
centre of the retort; the water in passing through the
heated material becomes converted into pure hydrogen
and per of carbon. It then passes into the third
retort to receive its dose of bi-carburet of hydrogen,
which is prepared from common tar, resin, or similar
substances, passing or dropping on the red hot chain,
from a syphon tube which regulates its supply. This
causes the tar, or melted resin, to throw off an abund-
ance of bi-carburet of hydrogen gas. The gases being
mixed in this manner, aro immediately conveyed into
the gasometer for use, without any purifying vessels
whatever, none being required. 4 •
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