of the furnace; then ceasing to be impelled by this force they settle by their own gravity, while the smoke which has not been and could not be impelled into a space, where, from its structure there can be no current, ascends by the continued force of the furnace. This improvement in the structure of the smoke pipe is applicable to steam-boats and to standing engines, and is of great value from the security it affords against fire by cinders."

If this is really as great an improvement as the Patentee seems to consider it, how much is it to be regretted that he has not either in the description or the drawing, shown us what is the form of construction to which he attaches so much importance.

The Patentee says, in conclusion, that he claims, first, the combination of the roller n, with a pinion i, on the shaft of the rotary engine, and the rollers communi. cating the force of the engine (by friction we presume), to the driving wheels of the locomotive engine; together with the mode of increasing or diminishing the rolling friction of the same upon each other, and upon the driving wheels, and of the driving wheels upon the rail; secondly, the combination with a locomotive engine of a smoke pipe, constructed with a recess out of, or aside from, the current, so that the cinders may be thrown into it by the draft; thirdly, the combination of a lever with the hinder bearing wheels on each side, to throw the weight of the engine upon the driving wheels; and fourthly, the combination of levers with the bearing wheels, to change the direction of the bearing wheels conformably to the bends of the road.—[Inrolled in the Inrolment Office, September, 1835.]

To JAMES BROWN, of Esk Mills, in the parish of Pennycuick, North Britain, paper-maker, for his invention of a certain improvement or certain improvements in machinery or apparatus for making paper.-[Sealed 18th May, 1836.]

THESE improvements in machinery or apparatus for making paper, have for their object a better application of a vacuum under the endless wire cloth, or web, of paper-making machines, for the purpose of more effectu: ally withdrawing the water from the paper-pulp as it passes from the pulp-vat to the couching roller; or to that part where the sheet of partially-drained pulp is taken up from the web, to be pressed or squeezed by rollers, to express the remaining portion of water preparatory to the rolling or pressing operation.

The Patentee states, that he is aware a vacuum has been heretofore applied to various paper-making machines, and more particularly to that description called cylinder machines, or rotary machines, in which the endless wire web, or cloth, is passed around a cylinder or drum, which revolves with the endless web; the vacuum being applied in the inside of such cylinder in various ways but in all instances the box or chamber in which the vacuum is formed, and over which the endless web passes, carrying the paper pulp, has been invariably covered with some kind of perforated lid or cover, intervening between the interior of the box and the underside of the endless wire web, or cloth, thereby impeding the effective operation of the vacuum.

The present improvements apply more particularly to the horizontal or Fourdrinier paper-making machine, in which the endless wire cloth, or web, is passed over

or along a horizontal table, formed by small supporting rollers; the pulp being partially drained as it proceeds from the pulp-vat to the couching roller. The novelty now proposed consists in applying the vacuum in a box or chamber under the horizontal wire cloth, or web, without any cylinder, and more particularly without any perforated covering or lid intervening between the said box or chamber, and the underside of the wire web, the wire cloth passing over the otherwise open box with the paper pulp, where it is equally and at all parts affected by the vacuum, without its operation being uninterrupted by any perforated lid or cover, or other intervening substance.

Plate II., fig. 3, is a sectional diagram of the operative parts of a Fourdrinier machine, taken longitudinally, with the improvement applied thereto : a, is the spout or shoot from which the paper pulp (shown by a dotted line) flows on to the endless wire cloth, or web, b, b, b; which web is supported by a series of small rollers c, c, c, and passed over the usual supporting and tension rollers d, d, to the couching roller e, from which the paper is carried in the ordinary manner.

The box or chamber f, in which the vacuum is formed, is placed directly under the endless wire web, supported in any convenient manner; several of the usual small rollers being removed to make room for it.

Fig. 4, is a plan or horizontal view of the box detached from the machine; fig. 5, is a cross section; and fig. 6, a longitudinal section of the same: g, g, are the sides and ends of the box, the top edge of which should be covered with leather for the endless web to pass over: h, is the pipe or passage for the exit of the air and water drawn through the wire web

VOL. X.

G

by the air pump; or this pipe may be connected to the condensing chamber i, where a vacuum may be formed by the condensation of steam therein, as is well known to all practical men, the condensed steam, air, and water, being drawn off by the pipe or passage k.

In order to make paper of different widths or sizes, the box or the space over which the endless web passes, exposed to the action of the vacuum, must be capable of being enlarged or contracted, so as to prevent the air being drawn through any part of the endless web, which is not covered by paper pulp. In order to effect this, it is proposed to construct the box or chamber with two small sliding pieces or shutters 1, 1, placed at the ends of the box, and next the underside of the endless wire web; and by moving these sliding pieces or shutters outward or inward, the open space over which the endless web and pulp passes, exposed to the vacuum chamber, may be enlarged or contracted at pleasure, and the vacuum made to operate upon a greater or less width of the paper pulp.

In conclusion, the Patentee says, " I would remark, that I do not intend to claim, as my invention, the application of a vacuum to all kinds of paper-making machines, as I am well aware that the same has been repeatedly applied to this purpose in cylindrical or rotary machines, or those in which a rotary cylinder is employed; but I do claim, as my invention, the application of the same to the horizontal web or wire-cloth of a Fourdrinier machine, in the manner herein described; that is to say, without the intervention of any cylinder, or any other thing intervening between the open space of the box or chamber in which the vacuum is produced, and the endless web or wire-cloth which carries the

paper pulp: at the same time, I would remark, that proper arrangements may be made to support the wire web if thought necessary.”—[Inrolled in the Rolls Chapel Office, November, 1836.]

Specification drawn by Messrs. Newton and Berry.

WROUGHT-IRON ROOFS FOR BUILDINGS.

To the Editor of the London Journal of Arts and Sciences.

SIR,-On a recent inspection of the works of the London and Birmingham Railway, now rapidly proceeding at Camden Town, I observed a very ingenious and simple construction of wrought-iron framing for a roof, erecting over what I understand to be the enginehouse of the London depot. It is formed of slight Tshaped iron, and angle iron bars, with small round rods securely bolted together. I recollect some years ago seeing a roof of a somewhat similar structure erected at the manufactory of Mr. Twells, in Ann-street, Birmingham, which roof was, as I understood, designed by your ingenious friend, Dr. Church, of that town. I do not know who designed the roof now erecting at the railway depot, but I presume Messrs. Cubitt, the eminent builders of Gray's Inn-road, as I am informed they are contractors for the whole of the works.

The framing of the roof in question at the railway is one of the lightest and strongest, for its weight of metal, that I have seen, excepting the one at Birmingham, to which I have alluded, and to which I decidedly give the preference. No account of either is, I believe, published, but I hope, through the medium of your