MESSRS. EDITORS.—In No. 10, Scientific American, you expect some of your friends in Muncy to prove how much the small wheel slides that is secured on the axle with two wheels of double diameter, (6 feet,) I will answer ; it will slide exactly the whole of its circumference, and roll the whole of its circumference, which is 3'14159X3=9'42477X, 2=18'84954. We measure the distance which the large wheels travel by the point of tread upon the rail, which is a perpendicular line drawn through the axis, consequently the axis is drawn through a space of 18'84954 feet in one revolution of the large wheels, therefore, as the small wheel makes only one revolution, and its axis passes through an amount of space double its circumference, it follows, that it must slide 9'42477 feet. The error which you also wish pointed out is the use of the word will not slide ; it was superfluous. Am I right *R. M. B. Muncy, Pa., Nov. 24th, 1852. [R. M. B. is right; the communications received on this'subject have been “ legion. List of Patent Claims FOR THE WEEK ENDING NOVEMBER 23, 1852 Swinging Churns—By Wm. F.&Nathan Davis, of Castleton, Vt.: We claim the combination of the swing slotted board wheel, rock shaftj and lever, for the purpose of producing two complete motions of the da,h, from one full oscillation of the pendulum bars. Bubstan tially as described, to be denominated the “ Oscillating Double-Actjng Dash Churn." Pincers for Operating Pile WiREs-By Augustus Faulkner, of Walpole, N. H. : I claim the manner described of constructing and operating the claw, for withdrawing. carrying, replacing, and releasing the figuring wires,by ma king one of the jaws fixed, and providing it with a pin or projection extending into a suitable slot in the sliding part of the claw, so that as said part moves back aod forth, in contact with the fixed part of the jaw, the pin or projection therein will, when the figuring wire is to be seized, keep it in position for being propeily caught in the claw, and when it is to be released, will prevent it from moving with the sliding jaw, as set forth. Spaces for Setting Type—E. C. Harmon. of Troy, Ohio : I claim the cyma racta, or other more suitable shaped elastic space, for facilitating the art of setting type, or for saving the time and labor usually expended in “ spacing out,:” ' thin spacing,” regulating the distance of words in the same line from one another, and “ correcting proof,” in the manner set forth. Fastening Palings to Rails in Iron Fences. —By Geo. Hess, of Easton, Pa.: I claim the circular projection, or its equivalent, on the rail and lower part of the paling, in combination with a corresponding cavity on the lower rail, so arranged that by giving a partial rotation to said rail the palings wil 1 be c amped to the rails, in the manner described. Drying Paints—By Heman S. Lucas, of Chester, Mass.: I claim the process of treating magnesian mineral, such as serpentine silicates of magnesia and iron, and similar rocks, by mineral acids, to prepare from the sedimentary or insolubl e, or undecom- posed portions of such rocks or mineral product, which I call a basis, to be used in the preparation of pigments, as set forth. Harvesters—By Johu H. Manny, of Waddams' Grove. Ill.: I claim, first, the arrangement of the track scraper and driving wheel, in such a manner that the latter, while the machine is cutting one swath, will run in the track cleared by the former, when the machine was cutting the previous swath, as set forth. Second, the projections on the under side of the upper bars of the finger, in combination with the chamfer or recess on the lower inside corners of said bars, to counteract the tendency of wire grass and other fibrous obstructions to pass in between the cutter bar, and the sides of the recess in the upper part of the fi nger in which it is guided. Third, forming the guard fingers of two parts, interlocked at the point, substantially as set forth, so that the grass cannot lodge in the joint and form an impediment to their entering between the stalks of the standing grain, l!'ourth, in combination with a rocker stand or seat, a removable platform, constructed with a wing that extends from the outer end of the cutter, over the frame, and holds up the butts of the straws above the stubble, which otherwise would obstruct the discharge of the grain from the platform, substantially as set forth. Printing Presses—By Chas. Montague, of Pitts- field, Mass.: I claim placing the bed-plate in a vertical position, when a reciprocating motion is imparted to it, by which the impressions can be made at each forward movement of the said bed-plate, as set forth. I also claim the combination of the vertically acting bed, with a cylinder or cylinders, arranged in such a manner that the forward movement of the bed will impart motion to the cylinder or cylinders, to give or take an impression and allow said cylinder or cylinders, to remain stationary during the return movement of the bed, substantially as set forth. Boot TREES-By David Sadleir, of McWilliams- towfl, Pa.: I claim, first, the arrangement and combination of the levers, friction rollers, screw, and slide, or their equivalents, with the back part of the tree, which, when constructed, all bed closely therein, for the purpose described. Printing PRESSES—By A. II. Cragin, M. Buck, J. H Buck and F. A. rreuney (assignors to A EI.Ora- O'in) , of Lebanon, N.H. : We claim, first, the arrangement and combination of the movements, in connection with the bed, by which an extent of motion is imparted to the said bed, much larger than that of the sweep of the operating crank, whilst the whole of the said movements only occupy the space within the frame work of the press below the bed, >he pinion shaft haviDg pinions upon it, which gear into stationary racks, 13 il, made fast to the sides of the frame, and into racks, 0 0, secured to the underside of the bed, the forked lever, or its equivalent, having its forked extremities connected to the said pinion shaft, and its opposite end j ointed to the lever that rises from the oscillating shaft, and the pitman connecting the said lever with the crank on the driving shaft, or the equivalents of the said movements, when combined and operating as set forth; disclaiming, however, the principle of imparting. motion to a printing press, bydirect application of' power to the bed. Second, the combination and arrangement of the pressure cylinder and the bed with the conveying bands, nippers, and cams for operating the said. nip- pars, as set forth.' Third, the arrangement of the upper and lower tables with the pressure cylinder, bed, conveying bands, nippers, and cams for operating the nippers in such a manner that an impression can be made at each right and each left movement of the form under the cylinder, and the sheets be deposited after receiving their impressions upon the said lower tables, substantially as set forth. WHifflktree -By D. C. Williams, of Madison, Ohio : I claim a shaft with the ends bent at right angles. and the lever making part of the same, arran- « «««. «::. i operating as set forth. Machine for Drilling Stone—By J. J. Couch, of Philadelphia, Pa : I claim making the drill rod to slide through the piston rod, as set forth. I also claim the combination of the rocker lever, the wedge, the bolt within the lever, the two cam plates, the spring catch, the spring, and a projection, as applied to the drill shaft, the carriage or block, and the sideways thereof, and made to operate together, and to actuate the drill, substantially as set forth. RE-ISSUE. Steam BOILERS-Oadwallader Evans, of Pittsburgh, Pa. Originally patented April 15, 1839 : I claim the combination of a fusible alloy confined in a cup tube, or case, with a metallic stem, rod, or other fixture, not fusible at the melting temperature of thealloy, which stem, rod, or other fixture, is held or kept in position whilst the alloy remains hard ; but when said alloy is fused, said stem, or its equivalent, can move or have motion, by which liberty to move any valve may be liberated, or caused to open and let steam escape, or any alarm may be let off, or any index moved, so that this combination may act as an alarm indicator, or safety apparatus. Also, in combination with said alloy and plug, the heavy slotted weight, lever, or its equivalent, and safety or escape valve and its ordinary weight, acting in the manner and for the purpose described.