which must be kept warm by laying upon the hot plate B under which the flue to convey the heated air from the furnace passes; then beat it out into a flat sheet, and pass over it the preparatory roller, as shewn in drawing C, until you have made it of the thickness required. When the sheet is thus formed, a board of sufficient size to receive the sheet when finished is passed through the rollers from behind, the nose of which board is chamfered away, so as easily to pass under the lead bearing the composition, which of course is still warm. The board bearing the composition on the lead is then passed back between the rollers, and comes out on the back side of the press, where are affixed cutters, as shewn on the drawing D, which are turned round by a pinion, taking in the great pinion which carries the rollers. These cutters slide on the bar, and may be put more or less apart as the sheet may be required of a greater or less width. In all the foregoing receipts tar is preferred to any other bituminous substance. EXPLANATION of the DRAWINGS. (See Plate II.) B, iron plate on which the lead rests. The shape of the bottom of the crock or boiler is marked by the dotted lines. 1, the lead which carries the cutters through the composition. 2, the bar, which being driven to and fro, drives the beaters in the boiler. The beaters are provided with flat iron plates at their feet, which travel on a pin, and scrape the bottom of the boiler. 3, the pinion which carries the cutters. 4, the pinion which carries the rollers. C, the preparatory roller loaded with stones. Specification Specification of the Patent granted to JOHN WILLIAM With a Plate. To all to whom these presents shall come, &c. Now KNOW YE, that I the said John William Lloyd, in compliance with and in performance of the aforesaid proviso in the said in part recited Letters Patent contained, do by this present instrument, in writing, declare that my said invention is herein particularly described. Whereas the wheels of carriages commonly in their progressive motion turn around and bear upon a fixed axis or axletree, whereby very considerable heat and friction is occasioned to the axis or axle-tree, which greatly impedes the carriages so drawn, to the great strain and detriment of the animal or animals that draw them: Now, in order to prevent the aforementioned heat, and also to reduce the aforementioned friction occasioned by wheels turning round and bearing upon a fixed axis or axle-tree, I so form and contrive the axis or axle-tree, that it shall turn round with and bear between what I denominate antifriction rollers or wheels as described in the drawing Fig. 5. (Plate III.) which antifriction rollers or wheels I commonly caused to be made, and recommended to be made, in diameter as near one half the diameter of the wheel which they are meant to assist as may be found most convenient. If the diameter of the aforesaid antifriction rollers or wheels are increased beyond this rule, they will be inconvenient in various respects; if they are decreased VOL. XI. SECOND SERIES. D decreased the assistance they are meant to afford will be decreased also; but the dimensions of the aforementioned antifriction rollers or wheels may be varied according to the weight of the carriages they are applied to; the said antifriction rollers or wheels may be made of pig-iron cast, or of common iron, brass, mixed metal, or wood with a hoop round the rim, or of any other hard substance that may be thought more economical. The antifriction rollers or wheels may overlap each other, or their rims may face each other, as described in the drawing Figs. 5 and 18. Sometimes I cause the antifriction rollers or wheels to turn round on spindles, pins, or gudgeons (made of malled or pig-iron) as described in the drawing, Figs. 2a, 2d, and 4. Sometimes I make the antifriction rollers or wheels turn by pivots or axles, fixed through their centres; the points, ends, or extremities of which pivots or axles I introduce into and well secure in sockets firmly fixed in a frame, or some other steadfast, made of iron, or some other substance sufficiently strong to support them, as represented in the drawing, Figs. 12 and 18. When I cause the antifriction rollers or wheels to turn round by pivots or axes fixed through their centres and confined in sockets, as herein before described in the drawing, Figs. 12 and 18, I then commonly place such frame or steadfast under the bottom of the carriage which the antifriction rollers or wheels are meant to assist; and perhaps that manner of fixing them may be best suited to slow carriages, as carts and waggons. Antifriction rollers or wheels which turn on an axis, pin or gudgeon I commonly cause to be fixed on the bed of a mail-coach, or any other quick travelling carriage or gig, as represented in the drawings in Figs. 1 and 5. The axis, pin or gudgeon, whether it be fixed to the bed of the carriage or in any more convenient situation, must be fastened into blocks |