If this gun has not yet followed the course of the numerous "improved fire arms" which have been made the subject of previous patents, it is no doubt on the road. There are few subjects upon which so much misapplied ingenuity has been expended within four or five years, as upon that of fire arms. They have been destined to be the subjects of a report, and have then been laid upon the table; and, we believe that the single barrelled gun, with its single charge, will not be generally superceded, either for the use of the army, or of the sportsman.

11. For Revolving Flashing Lights for Light Houses; Benjamin F. Williams, Boston, Massachusetts, February 20.

The claim made under this patent is to the "rendering the revolving lights of light houses distinguishable from other revolving lights by means of vertical revolving shades, turned by wheels moving on a circular railway to the axis of which the shades are fixed, directly in front of the lights, which, when in motion, will cause the lights to appear and disappear in quick succession of sudden flashes."

12. For a machine for Pressing Hay, Cotton, &c.; Joseph C. Baldwin, Staunton, Augusta county, Virginia, February 22.

This press operates by means of double progressive levers, of the kind called the toggle joint. The levers are connected to each other by a curved rack which is moved back and forth by a pinion gearing into it, which straightens the pairs of levers alternately. One end of each pair works on a joint in the frame work, whilst the other ends operate on notches in the shaft of a follower, acting, respectively, on its opposite sides, and alternately, forcing it on, whilst they also alternately act as palls in holding it in place. The press is placed horizontally.

The specification of this patent has been amended, and the patent reissued; when we arrive at the reissue we expect to present it with an engraving.

13. For Protecting Plastered Walls and Ceilings from fire; Peter Naylor, city of New York, February 22.

(See Specification.)

14. For a Corn Sheller; Alonzo R. Dinsmore, Chester, Rockingham county, New Hampshire, February 24.

This is said to be an improvement on Harris' corn sheller, a notice of which will be found at p. 262, of vol. xvii. The rubbing boards, in this improved machine are to be curved, one of them being made convex, and the other concave, by which change of form it is said that the machine will be rendered more efficient. This may be so, but we see no reason to alter the opinion originally formed and expressed respecting it, which is that it will be found to be one of the least useful of the shelling machines.

15. For a Crane Excavator; William S. Otis, Civil Engineer, city of Philadelphia, February 24.

This apparatus is to be applied to the purpose of excavating in the constructing of railroads, and canals, and it has been used to a considerable extent by the inventor, and found to facilitate the operation to a very great extent. From the nature of the instrument its particular arrangement could only be made known by means of the apparatus itself, or of the draw

ings. The apparatus excavates "by means of certain appendages to a scraper of the ordinary construction, which scraper is to be worked by a crane, and is to take the earth immediately from the banks from which the excavations are to be made.

"Although the improvement consists mainly in the manner in which I employ the scraper for excavating by means of the crane, I do not make any claim to the mere using of the scraper by means of the crane, this having been before done; but what I do claim in the apparatus described, is the application of power to force the scraper forward against a bank, in the act of excavating, and to withdraw it at pleasure by the aid of a barrel, chains, and other apparatus, constructed and operating substantially in the manner des cribed, by which its sudden recoil will be prevented as it encounters any

unusual resistance."

There are some other claims referring to particular parts, as represented, which it is unnecessary to insert.

16. For an improvement in the manner of Preparing Caoutchouc, Gum Elastic, or Indian-rubber; Charles Goodyear, Boston, Massachusetts, Assignee of Nathaniel Hayward, Woburn, Middlesex county, Massachusetts, February 24.

(See Specification.)

17. For a Steam Apparatus; Abraham Patterson, Rush, Susquehanna county, Pennsylvania, February 26.

This apparatus is said to be a substitution for the ordinary steam cylinder, a steam gauge, or a safety valve; yet we venture to pedict that it will not be used for either purpose. In all its forms it consists of a cylindrical vessel, closed at its upper end, and open below, its lower end passing in between two concentric cylinders exactly in the manner of the gasometers used by chemists. Mercury is to be used to surround the first named cylinder, in the annular space within which it is to rise and fall, steam is to be admitted to cause it to rise, and to be condensed to cause it to fall. The claim is to "the employment of an apparatus constructed as herein described as a substitute for a steam cylinder and piston of a steam engine, and the safety valve of steam boilers. And I also claim the employment of mercury in the said apparatus for the double purpose of packing and steam gauge."

When this engine comes into beneficial use we will say more about it.

18. For improved Tailor's Shears; Rochus Heinisch, city of Newark, New Jersey, February 27.

This improvement consists in widening out and so forming certain parts of the bows of the shears, as to constitute a bearing for the hand in grasping and using them, rendering it more easy to exert the necessary force in cutting. This is, no doubt, a real improvement; the claims are to the so con structing the shears, as described.

112

SPECIFICATIONS OF AMERICAN PATENTS.

Specification of a Patent for a mode of protecting Plastered Walls and Ceilings against the effect of fire; granted to PETER NAYLOR, city of New York, February 22nd, 1839.

To all whom it may concern: Be it known that I, Peter Naylor, of the city of New York, in the State of New York, have invented a new and improved mode of protecting the walls and ceilings of such apartments as are usually finished with lath and plaster, against the effects of fire, by substituting perforated plates of metal for the laths of wood usually employed; and I do hereby declare that the following is a full and exact description thereof.

I take thin sheets of metal; preferring, so far as my experience has gone, tin plate, as prepared for the purpose of manufacturing tin ware, as I have reason to believe that the tinning protects the iron completely from the action of the lime used, and from oxidation generally. I do not intend, however, to confine myself in this particular, but to use any kind of sheet metal which I may find adapted to my purpose. When tin plate is used, the distance of the joist, or of the timbers generally to which it is attached, must be within the limits of the length of such plates,) but when sheet iron or other metal is employed, the distance may be greater.

I take the sheet metal which is to be used, and I punch numerous holes through it in the manner of a grater, using either a round, or chisel-edged, punch, as may be preferred; the diameter of these holes may be from an eighth to a quarter of an inch. When the plates have been so punched I nail them on to the joist, scantling, or studs, with the burred edges of the perforations outwards. For greater security I take strips of hoop iron which strips I nail on to the timbers, before nailing the sheet metal, and when this is done it would be difficult to heat the metal through its two thicknesses sufficiently to set fire to the timber, even without the protecting influence of the plaster.

The sheets of metal may be seamed together at their edges before nailing them on. When the sheet metal has been properly secured to the timbers I proceed to plaster the walls in the usual manner, omitting, however, the first rough coat which is necessary when laths of wood are employed. The plaster will pass through the numerous perforations in the sheet metal, and will be as securely keyed, and retained in place, as when done in the ordinary way. It has been found also, by experiments carefully performed, that the plaster will not flake off by a long continued heat so readily as it does from wooden laths, which warp and twist, and thereby aid in loosening the plaster.

What I claim as my invention, and desire to secure by letters patent, is the use of perforated sheet metal as a substitute for laths on walls and ceil. ings to be plastered, using and applying the same substantially in the manner herein set forth.

PETER NAYLOR.

Specification of a Patent for an improved Mould-board for a Plough; granted to SAMUEL WITHEROW, of Gettysburg, in the county of Adams, in the State of Pennsylvania, and DAVID PIERCE, of the city of Philadelphia, October, 1839. Patent assigned to Samuel Witherow.

To all whom it concerns: Be it known that we, Samuel Witherow of Gettysburgh, in the county of Adams and State of Pennsylvania, and David Pierce of the city of Philadelphia, in the same State, have invented an improvement in the manner of forming the mould boards of Ploughs, denominated by us the cycloidal mould board; and we do hereby declare that the following is a full and exact description thereof.

It is a principle resting on mathematical demonstration that a cycloidal arc, is that which offers the least resistance to a descending body; and it is hence deducible that an ascending body will pass up a cycloidal curve with less resistance than up any other.

The construction of our mould boards is dependent upon this principle. In forming them we employ the cycloidal curve in two ways, namely, to the formation of the concave of the mould board in the lines of ascent of the sward or furrow slice, in the act of ploughing. The second application of the cycloidal curve, is in the convex curve along the sole of the plough, constituting the part which enters and cuts the ground horizontally.

In the accompanying drawing, fig. 1, represents a mould board, A, being its point, and B, its heel; the line A, B, is that of the sole, constituting the lower edge which cuts the furrow slice horizontally. This curve in a plough which has been essayed, and has been found to answer well, was generated by a circle of eighteen inches in diameter.

In fig. 2, the curve C, D, E, may represent the cycloid generated by the circle F, the point D, which is that of the least curvature, corresponds with the point A, of the plough, fig. 1, the cycloidal line continuing to the hind part, or heel, at B. It will no doubt be advantageous to vary the curve according to the nature of the soil, a point to be determined by experience, but whatever variation may be found useful in this respect is still to be made in conformity with the principle upon which we proceed, namely, that of making it cycloidal. The line I, H, along the upper part of the mould

board, and in a plane parallel to that of the plane of the line A, B, we also make to fit the same cycloidal gauge.

In the plough which has been put in operation for the purpose of testing the principle, the lines of the ascent of the furrow slice, which govern the concavity of the mould board were regulated by a cycloidal gauge made to a curve, generated by a circle of sixteen inches in diameter. Let C, D, G, fig. 2, represent such a gauge, and the lines a1, a2, a3, fig. 1, be assumed as those of the ascent of the furrow slice on the mould board; in forming said board we place the gauge in the direction of the line a1, with the part D, which is that of least curvature at a1, and thus proceed on until we arrive at the hinder part, B, H, withdrawing, or lowering, the gauge at its lower end at each successive application, so that a smaller portion of the least curved portion towards D, and a larger portion of that towards C, shall touch the mould board; these successive depressions may be indicated by the divisions at b, upon the gauge. The degree in which the mould board shall curve, and hang over at H, for turning the furrow slice, may be varied according to the judgment of the maker, the curvature being governed by the diameter of the generating circle, and the degree in which the gauge is depressed at every successive application of it.

Having thus fully set forth the nature of our invention, and shown the manner in which we carry the same into operation, what we claim therein is the giving to our mould board the segment of a cycloid, convexly on its face in line leading from front to rear, and concavely in the lines of the ascent of the furrow slice, in the manner and for the purpose herein described. SAMUEL WITHEROW, DAVID PIERCE,

Remarks by the Patentee.-A principal object in ploughing is to pulverize the soil, and the only way in which this can be effected by the plough, is by bending the furrow slice on a curved surface, so formed as that it shall also twist it somewhat in the manner of a screw. Such a surface will be formed by taking a strip of iron and twisting it after the manner of a screw auger; and if there is given to this piece of iron a greater twist at one end than at the other, cycloidal curves may be thereby produced. Now as the curvature of the cycloidal mould board generally increases from the lowest to the highest point of ascent, it follows, necessarily, that the furrow slice in passing along it will be more and more bent as it ascends.

By forming the fore part of the mould board by means of that part of the cycloidal gauge which has the least curvature, and the hinder portion by that part which has the greatest, the bending of the furrow will continue, and be increased, as it passes horizontally, as well as in its ascent.

By forming the lines of ascent cycloidal concavely, and the horizontal lines cycloidal convexly, the twist in the mould board will gradually increase from the fore to the hinder part, as the curves contract, which will operate very advantageously in pulverizing the soil. The convex cycloidal form given to the horizontal lines will cause the furrow slice to leave the mould board in a direction well calculated to prevent it from falling off in segments. The advantages possessed by this mould board, as has been abundantly proved in practice, are, that it will run light, and that it will turn the furrow slice over in a connected sheet, well pulverized.