The bricks for the quoins and jambs may be made either solid or perforated; and with perpendicular holes, either circular, square, or octagonal, those in the quoins may be so arranged as to serve for ventilating shafts. Stone will be found equally applicable for the quoins and jambs, and the appearance of the work be thereby improved.

Illustrative Example of Hollow Brick Construction, as exhibited in one compartment of the Model Structure.

need oxie a botirilen galed exoid odt lo anolanomil ou souborobandana to moisalgo,dali (doid

Square Jamb

and Chimney Brick.

Section of a 1ft. 2in. Wall.

Internal door and Chimney Brick.

The above section is also illustrative of the construction adopted in H.R.H. Prince Albert's Model Houses. The span of the arches being increased over the Living Rooms to 10 feet 4 inches, with a proportionate addition to their rise. The external springers are of cast iron, with brick cores, connected by wrought iron tie rods.

The French hollow brick, which were made in the Palace by their brick machine, constructed after the plan, somewhat of the tile machines, were different in form from the English. They are about 5 inches by 6, with square holes through the brick. They are much stronger than the English. When put under pressure, it required about one-third more pressure to crush the French brick, than it did the English. The expense of manufacture is about the same. It is said, that in some late excavations in England, hollow brick have been found among the Roman remains in good preservation, and portions of wall joined together not materially different from those of the present day.

From the observation I was enabled to make in relation to this improvement, it seems to me one of great practical importance, and which can be readily introduced into this country, and is certainly of as much importance to us as to any other nation.*

COMPRESSED TREE-NAILS FOR RAILROADS.-In this class, Ransom and May, of Ipswich, England, exhibited patent compressed treenails and wedges for railways, for which a Medal was awarded. This is a very valuable improvement, and is being very generally introduced upon the Railroads in Europe, more than 2,000 miles being laid with them, and would doubtless prove equally advantageous in this country. A railway chair, as it is called, in which the rails rest, of cast iron, of from 20 to 40 lbs. weight, is secured

*NOTE. Since this report was prepared, I have been informed that arrangements are already making for the introduction of hollow brick in this State. Mr. Joseph E. Holmes, of Fishkill Landing, who was at the World's Fair as the representative of Dicks' Anti Friction Presses, and a most intelligent and observing mechanic, has since his return, in connection with Mr. F. B. Taylor, invented machinery for the manufacture of hollow brick for building purposes. I am rejoiced at this, and cannot doubt Mr. Holmes' success.

E.-1852.

by wedges of compressed wood, the chairs being fastened to sleepers of wood by compressed tree-nails. These latter are cylinders of dry oak, compressed by forcing them into iron molds with a conical orifice; whilst in the mold, steam heat is applied, and the whole afterwards allowed to cool; the wood is afterwards forced out, and is then a cylinder of 1 inch drum for 4 inches of its length, and conical for 1 inches more. These tree-nails or pins are used for nailing the chairs to the sleepers; and as they swell with the moisture of the earth, they form a tight but slightly elastic fastening; and railways thus fastened are smoother than those in which metal fastenings are used.

The Great Hydraulic or Brittania Press, part of the great hydraulic apparatus with which the Brittania bridge over the Menai Straits was elevated, was on exhibition-said to be the most powerful ever constructed. The greatest weight lifted by the press at the bridge, was 1,144 tons-the quantity of water used for each six feet lift, 81 gallons. The Engineer, Mr. Edwin Clark, in his work on the Brittania and Conway Bridges, says, that "the pressure at three tons per circular inch equals 3,819 tons per square inch, which would raise a column of water 5.41 miles in height: this pressure would, therefore, be sufficient to throw a column of water over the highest mountains on the globe."

A Centrifugal Pump, called Appold's, was awarded a Council Medal. It was of great simplicity, and performed its work with a rapidity and power that was astonishing.

The principle is thus illustrated:

"By means of a little wheel 12 inches in diameter, and 3 inches in width, with twisted apertures, radiating from an open central space, there was made to rise to the roof of the department where the pump was in operation, a mass of water, which produced a broad and continuous waterfall, sufficient to turn a powerful water wheel. The wheel was driven by an oscillating engine of the requisite power to produce the rapid revolution in the little wheel which did the work. The wheel itself contained one single gallon

of water, when its apertures were full; yet, by being made to revolve at the rate of 607 revolutions in a minute, it lifted no less than 1,800 gallons in the course of that time, so that it must have been filled and emptied about three times in the course of every revolution. In fact, the disc once under water, when it worked, may be said to carry the water through its apertures, in continued streams or threads, or more properly, cables of water, forced out at several spaces by the centrifugal power of its rapid rotation. The main use of this invention was for the purpose of draining fen or marshy land, for which it must prove of great value. J. Stuart Gwynne, of New-York, exhibited his Centrifugal pump, which he claimed was equal, if not superior to Appold's. His pump was received with great favor by practical men, and Mr. Gwynne has commenced their manufacture in England, and with every prospect of success. Its great simplicity as well as its power, certainly gave evidence of its acknowledged worth. In cases of fire, a pump on Mr. Gwynne's plan, with a discharge pipe of 9 inches in diameter, will throw 4,000 gallons per minute, and with a piston of 48 inches diameter, (the pump making 400 revolutions per minute,) the water could be raised from mines to a height of 120 feet. In mining districts, when water is required to be elevated to large heights, this pump promises many advantages over any we have seen.

CARRIAGES.-In connection with this class a sub-jury had charge of the carriages. There was a very extensive exhibition of these from various countries, illustrating the styles which pertain to each. There were several on exhibition from the United States, which were much lighter in their construction than those from other countries, especially those from England. A Prize Medal was awarded for a slide top buggy, and for a sporting wagon. Taking the whole exhibition in this sub-division together, it did not appear to be the most attractive, nor showing the progress which really has been made.

Sleighs were exhibited from Russia, Canada, United States, &c., in considerable variety, and attracted much notice from visitors,

but do not appear to have received awards from the Jurors. A very neat and highly finished pony sleigh, was sent from this city by James Goold & Co., which was much admired.

CLASS 6. Manufacturing Machines and Tools.—This department was the most interesting and important of any portion of the machinery in the Palace, and a very large number of Council Medals were awarded-the number being twenty-two, one of which to the United States for Dick's Anti-friction Presses, manufactured under the direction of Joseph E. Holmes, of Fishkill Landing, Dutchess County.

The anti-friction presses are modifications of a highly ingenious arrangement of cams and levers, by which any degree of purchase may be obtained, with comparatively, the absence of friction. The principal peculiarity is the employment of pairs of eccentrics or cams, which, on being made to perform a part of a revolution, increase the distance between the centers, and exert an effort in doing so, dependent on the degree of difference between the curve of the cam and a true circle, or in other words, on the rate of increase of the radius. An advantage belonging to this description of machine is, that by modifying the curvature of the cams, the leverage can be regulated to suit the work to which the instrument is applied. Thus in compressing cotton, hay, tobacco, or any other kind of goods, an increasing leverage is requisite, so that the power increases with the resistance. This, the hydraulic press cannot do, and this machine has great advantages in this respect. It is much cheaper, lighter, and less liable to get out of order than the hydraulic press, and works with the minimum of friction, and therefore with the greatest amount of available power.

The presses of various sizes and for different purposes exhibited, excited no little interest among scientific and practical machinists, and the universal tribute to its importance, was given by the unanimous award of the Council Medal by a Jury composed of the most distinguished men from various countries. The right to use it, a patent having been obtained in England-was disposed