stays, so long as the principle is substantially the same as herein before described and shown in drawings, sheets Nos. 1, 2, 3, 4, 5, 6, 7, 8,

and 9.

Seventhly. I also claim in connexion with the extension of the fire box into the body of the boiler, the introduction of metal or clay pipes, as shown in sheet 6, figures 4 and 5, and herein before described, for the purpose of heating the fresh supply of atmospheric air that may be introduced into the fire-box, and for distributing this air amongst the combustible gases evolved from the fire, so as to cause a better consumption of the fuel and a consequent consumption of the smoke where coal is used, either in locomotives or stationary engines. I do not mean to confine myself to any particular mode of letting in the air above the fire, nor to any particular mode of arranging the air pipes, which I propose to place in the fire box, so long as the principle remains substantially as hereinbefore described and shown in the said drawings, and although these air heating pipes are only shown in sheet 6; still, I mean to apply them to any and all the boilers described hereinbefore in this specification, or in other forms of boiler, and wherein the same principle can be introduced, and substantially in the manner hereinbefore described.

By forming a locomotive boiler with the prolongated fire box, advantage may be taken to indent the under side of boiler, as shown in sheet 6, figure 8, as to let the axle clear, whilst the centre of gravity of the engine is lowered in a corresponding degree, this being prevented in the usual form of boiler on account of the tubes being in the way of such indentation.

In witness whereof, I, the said Joseph Harrison, have hereunto set my hand this 11th day of February, 1852.

JOSEPH HARRISON.

For the Journal of the Franklin Institute.

Chesapeake and Delaware Canal Wheel for Raising Water.

The elevating wheel put up at Chesapeake City, at the commencement of the past canal season, presents some features worthy of note. It was constructed for the Chesapeake and Delaware Canal Company, by Merrick & Son, of Philadelphia, and was designed to supply water to the canal from Back Creek, (a tributary to the Elk River,) which communicates with Chesapeake Bay. The constructors guaranteed that it should raise 200,000 cubic feet of water per hour, with a consumption of 560 pounds of anthracite coal.

The wheel is 39 feet diameter and 10 feet in width, having iron centres and rims or "shroudings," with wooden arms and buckets (twelve in number), the latter having curved backs, so made as to take up the water easily; the inlet openings are in the periphery, extending entirely across it, and the discharge openings in each side, near the centre of the wheel. Toothed segments, forming spur wheels 39 feet diameter at

pitch line and 11 inches face, 31 inches pitch, are bolted, one on each rim, and gear into two pinions 4 feet diameter, keyed to the fly wheel shaft of a condensing beam engine, the cylinder of which is 36 inches diameter and 7 feet stroke. At the usual speed of the engine (24 revolutions per minute) the wheel makes 2,466 revolutions, and delivers the contents of 29 buckets. The "dip" of the wheel is maintained at 1 foot 8 inches by gates between the creek and feeding sluice, which are regulated by floats. The height between levels of water in sluice and discharging canal is 17 feet 3 inches. The total height to which the water has to be carried cannot be exactly estimated, from the fact that the buckets do not finish discharging until they pass the vertical centre line of the wheel; it is, however, very near 18 inches more, and may be so assumed, without much error-giving for the total height 18 feet 9 inches. No water goes off in the descending buckets, except that adhering to the sides.

Steam is supplied from four 42-inch boilers, 50 feet long, and is usually cut off at one-fourth the stroke of the piston. Heating surface, 1100 square feet.

The engine and wheel have been in successful operation for about six months, until the canal closed. Prior to its acceptance by the Company, it was tried on the 12th to 17th July, when the work done and coal consumed, with other data, were carefully noted. The following results were obtained on this trial, which lasted 78 hours:

Average pressure of steam in steam chests, 52 lbs. per square inch; vacuum, 23 inches of mercury; total coal consumed, 21 tons=613 lbs. per hour; quantity of water discharged per hour, 227,160 cubic feet, or at the rate of 539 pounds for 200,000 cubic feet; the useful effect produced was therefore 200,000 × 62112,500,000 pounds raised 171 feet =215,625,000 pounds raised 1 foot high by the consumption of 539 pounds fuel, or per pound fuel, 400,046 pounds of water, and per bushel of coal (94 pounds) =37,604,324, or 37 millions. The absolute effect produced, assuming the height raised at 18 feet 9 inches, would be 37,604,324 x 18.75

17.25

=40,707,050, or a duty of 403 millions.

It is intended during the coming season to take indicator cards from the cylinder, while the wheel is in operation, in order to determine the ratio of power and useful effect.

The discharge of water was determined as follows: A distance of 30 feet was measured in the length of the discharging canal, for which distance its width was the same, 151 inches. At distances of 10 feet, four measurements of depth of current were taken, (making twelve in all,) and their depth averaged, giving a mean depth, the product of which and the width represented the mean cross action. The velocity of the current was determined by repeated trials with a light floating body, and the use of a watch beating quarter seconds. Although not strictly accurate, the result obtained was probably as near the truth as it could be determined without the use of a waste-board.

X.