LIST OF IRISH PATENTS GRANTED IN

NOVEMBER, 1838.

Joseph Rock Cooper, for improvements in firearms. Nov. 6; 1838.

Jean Leandre Clement, for improvements in apparatus for ascertaining and indicating the rate of vessels passing through the water. Nov. 6.

Richard Thompson, for improvements in making a certain spirituous liquor, which he intends to denominate 66 Thompson's British Wine Brandy." Nov. 8.

John W. Fraser, for improvements in diving, or descending, and working in water, and for raising or floating, sunken and stranded vessels, and other bodies. Nov. 16.

John Henfrey, for improvements in the manufacture of hinges and joints, and in the machinery employed therein. Nov. 17.

Richard Eese, for certain improvements in drying corn, or other grain, seeds. Nov. 21.

Frederick Joseph Burnet, and Hippolyte F. Marquis de. Bouffet, for certain improvements in the manufacture of soap, &c. Nov. 29, 1838.

William Neale Clay, for improvements in the manufacture of iron, &c. Nov. 26.

Fauquet Delarue, jun., for certain improvements in printing. and fixing fast red, black, and other colours upon cotton, silk,woollen, and other fabrics without the usual process of dying. Nov. 29.

William Rattray, of Aberdeen, chemist, for certain improvements in the manufacture of gelatine size, and glue. [Omitted in the list for July.]

NOTES AND NOTICES.

Duty on Bricks.-"I wish you would stir up architects to get the duty off bricks: even the double duty taken off would be a boon in favour of the extension of taste. A meeting should be got up in London, to draw up a petition to parliament, which would soon be followed by the rest of the kingdom. In fact, there should be a regular agitation. I have seen the Marquis of Tweedale's 'brick-maker,' and think highly of it."-W. Thorold. Arch. Mag.

Steam-boats on Canals.-The Rev. J. W. M'Gauley, Professor of Natural Philosophy to the Board of Education, we understand, has at length succeeded in fabricating a machine for propelling boats on canals without raising a surge, which has been very detrimental to the banks, causing a considerable annual outlay to keep them in repair. The power will be derived from a steam-engine; but instead of the usual paddle-wheels, there will be a machine immerged in the water underneath the centre of the boat, the working of which will not cause the least ripple on the surface of the water. There will be a public test of the invention on the Grand Canal about a fortnight hence, with a boat fitted up under the immediate inspection of the Rev. gentleman.Dublin Post.

New Jetty at the London Dock.-A great improvement has been lately made in the London Dock, by the erection of a magnificent jetty, supported on massive piles, exteuding from the southwest quay, 800 feet across the large basin, affording a quay frontage on both sides for the loading of outward-bound ships of 1,600 feet. The jetty is 62

feet in width, and three lofty sheds, each 208 feet long by 48 feet wide, for the reception of goods and merchandise for exportation, are in the course of erection; one of these store-houses is already completed. There will be a space of 7 feet clear on each side of the warehouses. The erection of the jetty is said to have cost the London Dock Company not less than 60,0007., and it will afford great accommodation to the shipping, and particularly to the Sydney and Hobart Town ships. There are now eight large vessels bound to those places lying alongside the new jetty. They will all carry out a great number of emigrants.

Supplying St. Pancras with Water from Artesian Wells. We have been much surprised to see by the newspapers that this subject has been seriously thought of, and discussed in meetings at which some persons were present eminent for scientific knowledge. We thought it had been generally known that the sources which supply the London basin, ample as they are, are still limited. As a practical proof of this, it is only necessary to mention that the two great breweries which draw their supplies from wells which penetrate to the chalk, the one on the Middlesex, and the other on the Surrey side of the river, cannot both pump on the same day, and, by agreement, pump on different days. If a part of the Thames water above Richmond, where it is tolerably pure, could, by means of a deep shaft, be made to run into the basin, then, no doubt, the whole of London might be supplied from it, cheaper than is now done by surface-pipes. But, supposing this mode to be adopted, it would only prove sufficient for a century or two; for such would be the quantity of sand and mud carried down by the water of the Thames, that, unless it were filtered before it entered the shaft, it would, in time, solidify the under stratum. Amoug all the plans that have been devised for supplying London with water, we have no doubt whatever that the present mode by surface-pipes is the best, provided the water be drawn from pure sources. By being brought in in pipes covered by earth, the water is delivered at a lower temperature in summer, and a higher temperature in winter, and free from all those impurities to which an open watercourse is liable witness, for example, the New River. How to question. Perhaps the real object of the St. Pancras meeting was to hold the Artesian system in terrorem over the advocates of the surface system, in order to keep the water companies within bounds. Mr. Loudon.-Arch. Mag.

London and Greenwich Railway.-On Monday the whole line of this railway was opened to the public, and the number of passengers far exceeded the usual average. The distance to and from Greenwich was performed throughout on an average of 18 minutes. Several of the directors and principal shareholders in the company went to Greenwich and back.

Metropolitan Railway Map. - Now published, vol. xxix. of the Mechanics' Magazine, price 8s. 6d., illustrated with a Railway Map of the Metropolis, taking in a distance of 30 miles from the Post-o fice. The limits of the two-penny and three. penny post deliveries are also shown in the Map. The Metropolitan Railway Map alone, stitched in a wrapper, price 6d., and on fine paper, coloured, 1s. The Supplement to vol. xxix, price 6d. The Railway Map of England and Wales continues on sale, in a neat wrapper, price 6d.; and on fine paper, coloured, price ls.

VICTOR'S ROTARY STEAM-ENGINE. A patent was granted for this engine on the 19th of March, 1838, to Mr. Duchemin Victor, of Boulogne-sur-Mer, and the following description has been supplied to us by a friend of the in

ventor:

This rotary engine, to be worked by steam, or other aeriform fluids, has four moveable pieces or pistons, entering, by means of an exterior arrangement of machinery, into an interior and concentric cylinder, upon which the pressure is always equal, since it always presses simultaneously upon equal and opposite surfaces; its great cylinder is inwardly cylindric in all its parts, and is not cut for the passage of any piece, which advantages secure to it all the strength of the metal; it can also have a great diameter, and a great height from one base to the other. This engine can be made use of at any pressure, as well as with condenser and air pump, and its peculiar construction exempts it from those defects which are necessarily attached to engines of the ordinary construction.

Description of the engravings:-
Fig. 1, is an elevation of the engine.
Fig. 2, a side view.

Fig. 3, a section by CD.

Fig. 4, another section by A B, A C. a, in fig. 1, 2, 3, and 4, is the foundation plate.

b, is the exterior or great cylinder of the engine; it is shut at each extremity (fig. 3) by a ring, which forms, at the same time, the fixed and uneven part of a stuffing-box. The capacity between this cylinder and the interior cylinder (fig. 4) is divided into two equal parts by separations or abutments, which resist the pressure of the steam; these separations or abutments are furnished with blades, whose length is equal to the height of the interior cylinder, and these blades are squarely finished, in order that the part which, by means of small springs, will gradually approach to replace the part worn out, may be always of the same length.

c, is the interior and concentric cylinder; it is fixed upon the axle-tree. The four arms of this cylinder (fig. 4) are prolonged on the outside (fig. 1 and 3), and are grooved in their full length, sufficiently deep (fig. 3) to permit the pieces receiving the impulsion of the steam, and communicating the motion to the

axle-tree, to lodge themselves in, when they pass before the separations or abutments (fig. 4). This cylinder is so arranged at each extremity (fig. 4) as to allow of a ring (fig. 2 and 3) being fixed to it; this ring forms the part of the stuffing-box, whose surface is polished, and which moves itself with the interior cylinder. Small plates, fixed at the extremities of the arms (fig. 1, 3, and 4), complete the closing of the grooves. The moveable pieces acting as pistons (fig. 3 and 4) are furnished, as are also the separations or abutments, with blades, constantly pushed by small springs; these blades, by means of the peculiar arrangement of the extremities of the cylinder (fig. 3), prevent, on every side, the leakage of the steam. The outward motion of these blades is limited by small pins (fig. 3); small cavities in the arms (fig. 3 and 4) diminish the friction of the moveable pieces.

d, shows a cross, fixed upon the axletree at each extremity of the cylinder; the middle of each arm of the cross, placed precisely opposite the moveable pieces, serves to guide a sliding piece (fig. 2 and 3), which receives the motion on one side by a roller, and communicates it by the other to the moveable pieces, by means of a rod rolling through a small stuffing-box.

e, shows the pieces in which the rollers run. These pieces are fixed upon the foundation plate. The rollers, in the parts placed opposite the separations or abutments, run in parallel guides towards the axle (fig. 2), and approach it sufficiently to allow the moveable pieces to pass before these separations or abutments without touching them.

f, are the boxes, with bearings, in which turns the axle-tree of the engine. Regulating screws acting upon these bearings keep the axle-tree always, and in every way (notwithstanding the wearing out), in its proper position.

g, is the axle-tree of the engine, by which the motion is transmitted.

h, are the pipes and cock, for the admission of the steam into the cylinder. i, shows two cocks (fig. 1 and 3) permitting, alternately, the entrance of the steam into the cylinder, whilst its going out takes place by the other, according to the direction in which the engine works.

j, are two forked pipes (fig. 2 and 4),

serving alternately for the entrance or going out of the steam, which is introduced simultaneously upon equal and diametrically opposite surfaces, and acts constantly upon two of the four moveable pieces. It is to be remarked that at each time the steam goes out, it is only the quantity which was contained in the capacity between two moveable pieces.

k, is the pipe for the exit of the steam. 7, is the handle (fig. 1, 2 and 3) by which the engine can be put in motion, in one direction or in the other, or can be stopped with the greatest facility, since this handle operates at the same time upon the three cocks (fig. 1 and 3), by means of three tooth-wheels, one of which has thirty teeth, and the others forty. In the position where the handle is (fig. 3), the steam is introduced by the pipes on the left, and it goes out by those on the right. To reverse the motion, it is only necessary to place the handle, which is now a sixth part of a circle, on the left, in a similar position on the right. To stop the engine, the handle must be placed in a perpendicular direction.

In conclusion it is to be remaked, that this engine is extremely simple; all its parts can be easily examined by so arranging the foundation plate as to admit of one of its extremities being taken down, which would allow the exterior cylinder to be taken off.

PHILOSOPHY OF ROAD MAKING.-IRON FRAME AND WOODEN BLOCK ROAD.

Sir,-Amongst the mechanical arts tending to the progress of human civilisation, the first in importance, after that of printing, is the art of road-making. Printing circulates ideas, and roads circulate men and women, the originators of ideas; and they moreover, quicken and increase to an enormous extent the circulation of printed ideas. Viewed thus, it seems strange that, with the single exception of the process of macadamisation, all road-making in England -rail-road-making inclusive-is most unphilosophically performed.

Leaving out of the question the operations of levelling or preparing the ground for road-making, the first principle to bear in mind is, that the whole

surface be so bonded together that no part of it can be forced down below the level of the rest, by the heaviest load, concussion included, which may pass over it. Or, if the nature of the material or its mode of preparation preclude this, then every separate portion of which the surface is composed should possess sufficient breadth of bearing to ensure it against sinking by the passing weights. The heaviest load is probably a coalwaggon, weighing nearly two tons, and carrying in it a load of four tons. This will give a ton and a half to each wheel; add the momentum, and the frequent unequal bearings, with the falls from prominences into hollows, the wheels will frequently press with a weight of upwards of four tons each.

Let us now examine how far the various roads in use comply with the essential principles laid down.

A road may be bonded together either chemically or mechanically, or in both modes combined. An exemplification of the chemical bond is the concrete formed with hot lime and broken stone. A very hard and white road may be thus made; but the disadvantage of this bond is, that when once broken it will not again unite.

The conjoined chemical and mechanical bond is exemplified in the roadways of squared granite blocks, grouted with hot lime. The disadvantages of this is that the mechanical bond is imperfect, the stones being a series of wedges, only touching each other at their upper edges. The pressure of the loads soon breaks the chemical bond, and the stones are forced one below another, when the road becomes rapidly useless.

The mechanical bond may be subdivided into two kinds-that of pressure united with friction of surfaces-and that of adhesion, owing to the plastic nature of the material. The common Macadamised road of small pieces of granite is an example of pressure and friction united. The rough facets of the fragments of stone, being shaken into something like order, fitting against each other, are in that state firmly pressed downwards and laterally, by the passing loads and become a white inass. road can only be destroyed by positive wear, and it is repaired with perfect facility, a few days of passing loads restoring it to its level condition.

This