£herefor; making the rivet with the heads on one side only willfully ianswer the purpose of riveting with the heads all around, at the same time avoiding all the inconvenience arising from the use of the old rivets has well as the clinch.” Letters patent have also been granted for an improvement in weavers’ harness. A great deal of ingenuity has been exercised upon heddles, and smany improvements have been made; but, notwithstanding their apparent simplicity, none have been in use which appear for all purposes to give •entire satisfaction, particularly in weaving very fine fabrics. The heddle used in the harness above mentioned is made in the following manner: Six threads are braided together until the point is reached at which the loop is to be made. The strands are then divided into two parts of three each, and braided separately the length of the required loop; they are then all braided together again, the length required for the heddle. The process is simple; the work may be done by machinery; and apparently a very excellent article is produced. Where several shuttle boxes are used, a difficulty frequently arises in changing the boxes from the hanging of the shuttle to the picker. ... After the picker has been used for a length of time the steel points of the shuttle penetrate it, and when the shuttle is sent home the point frequently remains in the perforation in the picker; and as the picker is stationary, while the shuttle box with the shuttle rises or falls, there is great danger of breaking the boxes. A device has been patented this year whose object is to remedy this inconvenience, and consists simply in giving such form to the picker-cam as to cause the picker to move forward a short distance immediately after the shuttle is sent home, which carries the shuttle forward out of the way, and to retire to the proper position for allowing the boxes to be changed immediately. The remedy is simple and appears effectual, and the inconvenience it obviates is very considerable. A patent granted, several years ago, for the conservation of power and p. of shocks in throwing and stopping the shuttle, has this year been surrendered and reissued. Letters patent have been granted for improvements in looms for weaving ingrain carpeting and other fabrics where a great number of colors are used. The chief characteristic of this loom is arranging the parts in such a manner as to accommodate and operate four sets of shuttle boxes. The *machine is too complicated to be understood from any description I might here give. I will, however, present it so far as its general characteristics are given in the following preamble extracted from the patent: “The nature of my improvements in machinery for weaving two or three ply ingrain carpets consists, first, in the manner in which I construct and combine the cams for operating the lay, so as to give to it a vibratory intermittent motion. Second, in the manner in which I combine and operate four sets or series of shuttle boxes, said four sets or series being so arranged as to enable me to operate two of said sets or series coniy or the four together, as the fabric to be woven may require; the number of shuttle boxes in each set or series being varied at pleasure. Third, in the combination or organization of mechanism for raising and lowering certain of the aforesaid series of shuttle boxes, in the manner required to produce any given pattern or figure to be wrought. Fourth, in a certain combination or new organization of mechanism for operating the picker staffs or levers, by which the 'several shuttles are thrown in the order required. ” Fifth, in a certain peculiarimechanism or combination of parts, by which I am enabled to arrest the operation of the loom whenever the shuttle is thrown and does not properly enter the shuttle box intended to receive it. Sixth, in certain movable or turning guide plates applied itd certain parts of the loom frame, in order to prevent accidents from occurring to the loom or a shuttle whenever the latter projects from a shuttle box.” . * : An improvement has been patented this year in looms for weaving twilled goods, whose simplicity and importance entitle it to notice. The “following extract from the patent renders it unnecessary for me to describe it : - “In weaving twilled fabrics it is known that the sets of harness have to be shifted in succession, whether consisting of three or more, commencing with the first, the second, then the third, &c., and back again to the first; this has generally been done by a series of cams, one forced treddle requiring the camshaft to move very slowly, and rendering an “additional cam shaft necessary either for the harness cams or the shuttle cams. To obviate this, I make the harness cams to slide endwise on the shaft, and provide them each with a cylindrical hub, the periphery of which has as many grooves cut. in it as there are treddles to be worked by it in succession; these grooves run in the direction of the circumference nearly the whole circuit, but towards the end the first takes a diagonal direction and runs into the second, and in like manner the 3 second runs into the third, and the third then crosses the second and runs into the first, the inclination of the groove uniting the third and first and crossing the second being greater than that which unites the first and second and the second and third. These grooves receive a feather, which turns on a stud pin projecting from the frame, so that as the cam shaft rotates (supposing the feather to be in the first groove) the first groove Hruns on the feather, and when it becomes diagonal to run into the second the feather turns on the stud and runs into the second groove, thereby shifting the cam to the second treddle. In like manner it is shifted to the third and then back to the first, the ends of the turning feather being rounded to prevent catching on the fillets between the grooves, where the third groove crosses the second to run into the first.” Letters patent have been granted for an improvement in the jacquard, which is entitled to particular notice. As the whole duty of arranging the warp for the production of the figure devolves upon this auxiliary to the loom, the endless variety of its operations naturally introduces great com“plexity, and corresponding liability to derangement. These evils should be guarded against with a watchfulness ever upon the alert; and, to obviate them without impairing the versatility of the jacquard, the inventor of these improvements has successfully exercised his ingenuity. Fortuonately, the following extract from the patent will shed sufficient light upon the invention to enable the weaver to understand its distinctive features: “In the jacquard frame, as heretofore made and now used, the trap boards through which the tail cords pass, and by which they are lifted, are each operated by separate levers, thus requiring as many levers and separate operations as there are trap boards; and in the mode of mounting to form the harness as at present practised, each division of the tail cords *(all that pass through one trap board I will call a division) is in connexion with one color only, (it will be understood that when I speak of one color only, I mean also the threads connected with the mails of one pair of lifters,) and that, as a necessary consequence, when the threads of one color (or combination of colors in a pair of lifters) are to be used to interweave the picks, the cards must be shifted and a new card presented for each pick. “The object of my improvement is to simplify the structure and operation; first, by connecting all the trap boards, by horizontal slides, with a vertically sliding frame, operated by one single lever, so that all the trap boards are lifted together, the lifting of the tail cords being governed by the sliding of the trap boards, that are provided with notched holes through, which the cords pass, so that when the trap boards are shifted (which is done by cams on a rotating shaft turned by the sliding of the trap board frame, or any other intermitting movement) the knots on the tail cords, which have been shifted by the needles, are caught and lifted ; and, secondly, by connecting the tail cords that pass through one trap board with the mails on two different pairs of levers, so that the mails of each lifter of one color, or one set of colors, are connected with two trap boards, and so of the other colors. The advantage of this arrangement is, that one card only is required for each lash, as the interweaving of one color can be effected by one card, in consequence of the connexion of the mails of each lifter of one color, each with two separate, trap boards, while, by the old plan, it is necessary to shift the needles to interweave the same color, as, the shifting of the threads of one color can only be done by shifting then needles by a change of cards, in consequence of the connexion of all the mails of one color or set of colors with one trap board.” I must here close my remarks upon looms and upon machinery for the manufacture of fibrous and textile fabrics, with sincere regret that the complicated character of the machinery has in many instances precluded the possibility of doing justice to valuable interesting and beautiful inventions, highly honorable to the inventors, and full of promise of future important developments. ... on . . . FiRE ARMs And IMPLEMENTS OF WAR. . In this class but one patent has been granted within the year, and that was for improvements in the machinery for welding wrought iron or steel cannon. The sections to be welded are prepared in the form of rings, which are welded in a matrix, and around a core, by a piston operated by a hydraulic press. When the welding.has progressed the length of the matrix, that portion of the gun which is already welded is removed, and staves, properly prepared, are placed around the interior of the matrix, re-o | ducing its diameter sufficiently to adapt it to the next section of the gun. The welding then goes on as before until the second section is formed, when the matrix is again reduced as before to adapt it to the third section, and these operations are continued until the welding is finished. As thes, interior of the matrix is the frustrum of a cone, it is readily perceived that, the staves may have such relative proportions of length and thickness as i to preserve the proper taper of the exterior of the gun. ... There are many, details of the parts and operations given by the inventor which, in this: place; are unnecessary.' . . . . . . o a The ordinary mode of giving the welding heat appears to be adopted?

by the inventor; and the injury which the iron is liable to sustain in heating is in no way guarded against. There are doubtless great obsta-5, cles in the way of welding large masses of iron or steel, independent of those which arise from injury in heating, some of which are removed by: the inventor; but this is not enough to insure the safety of large wrought iron guns; and until the quality of the masses to be joined can be de-n pended upon, no process of welding can give security. Each imperfection in a wrought iron gun is increased by every strain by every discharge; and a gun which might be safe in ordinary use might be rendered unsafer by the very trials which are resorted to for proving it. The fact that a wrought iron gun has sustained the shock of heavy and repeated chargest is often the very reason why it will never resist another. It is a perfectly well established fact that wrought iron, by repeated jars or strains, ceases: to be fibrous, and becomes crystalline; and a bar of the best wrought iron may be subjected to tension until, when struck by a hammer, it will” fly into small pieces. It is often observed in chain cables that, thoser, which have resisted the severest trials are broken by an inconsiderable: strain, and the fracture is crystalline. If, therefore, in welding, successo is perfect, the iron will constantly deteriorate by the strains incident too discharges until its strength is destroyed, and it bursts after repeated trialso have won for it unwavering confidence. Among others, there is this important difference between cast and wrought iron—powerful shocks cause wrought iron to deteriorate, while cast iron, under similar circumstances, remains substantially the same or breaks. A shock, therefore, which cast iron has once resisted, it will probably resist again; but when the strain is great upon wrought iron, it probably will not resist the same strain again; and the gun which has resisted the severest trials is perhaps the least likely to be safe.

NAVIGATION AND MARINE IMPLEMENTS.

But few improvements belonging to this class have been patented within the year. Ships and boats.—Letters patent have been granted for an improvement in the hatches of ships. With all the precaution which can be used, water will sometimes insinuate itself under the hatch. The object of the inventor is not to prevent this, but to discharge the water which accumulates around the hatch upon the deck. To effect this the groove into which the bed on the hatch fits is made to communicate with severalo holes through the curb or hatch frame, opening on the outside. If, then; the water gets under the edge of the hatch, and into the groove, it willo immediately be discharged through the above-mentioned holes upon the deck. To prevent the entrance of water through these perforations, each: is furnished with a valve opening outward only. Letters patent have also been granted for improvements in portable." boats. The frame of the boat consists of four hollow India-rubber cylinders, connected together in a rectangular form. When used the cylinderss are inflated with air, and a strong water-tight cloth is placed under them, its edges being brought up over the cylinders, and fastened in some convenient way. When the cylinders are not inflated, the boat can be folded for transportation in any desirable way. Steering.—An improvement has this year been patented in machinery for steering vessels, which is important in preventing such sudden jerks

upon the steering apparatus as are occasioned by the slack of the tiller rope. The improvement will be understood by reference to the following: extract from the patent: o “The nature of our invention consists in the employment of two groove. rollers, mounted in appropriate bearings, one above the other, on the helm, the upper one being on the shaft of the tiller wheel, and mounting the tiller rope, by first attaching one end of it to one side of and near the extremity of the helm, passing it through a block attached to the side of the vessel; then through a block attached to the same side of the helm; then, over the upper drum, and in the first groove; then under the lower drum; then around the upper drum, and in the second groove; then around the lower drum, in the second groove, and so on to the end, each time crossing the rope, to insure the bight thereof; and then from the upper drum to a block attached to the side of the helm, and just opposite to the attachment of the rope on the other side; and thence carrying the rope through a block at the side of the vessel; and then tying the end to the helm, at a point just opposite the block on the other side, so that by this arrangement: of the grooved drums, and the disposition of the tiller rope, it (the rope) is prevented from slipping and overriding, and at the same time it is prevented from making slack as the helm vibrates, for the slack is taken up. on one side as fast as it is made on the other, and the rope is also prevented from chafing.” Propellers.-The subject of propelling, heretofore so fertile in inventions, appears within the last year to have received but little attention. But five patents have been granted for improvements in propellers, and comparatively few applications have been rejected. Those patented this year do not possess a commanding importance. One patent has been granted for a peculiar mode of propelling, by discharging jets of water from the stern. The mechanism is quite ingenious, but complicated to a degree that renders it difficult to describe, without possessing the degree of usefulness which would justify the effort. As the speed of the vessel, and the velocity with which the screw propeller revolves, require for advantageous action the floats at different times to stand at different angles with the shaft, a mode of adjusting the angles: of the floats according to circumstances has been invented and patented within the last year. The device differs but little from those resorted to for adjusting the wings of wind-mills, to adapt them to similar variations. I will mention one other improvement in propellers, which has been patented. The vessel is principally propelled (according to the theory of: the inventor) by any ordinary means; and his improvement consists in placing a reaction water-wheel at the bow of the vessel, with its axis parallel to the keel, and so constructed as to receive the water at the centre of the wheel, and discharge it at the sides between inclined floats, so as to give a revolving motion to the water-wheel, and the power of the waterwheel is then communicated to the main shaft of the paddle-wheel in any convenient way. The foregoing descriptions will give an idea of the character of inventions.patented within the year in this department. A great improvement is still demanded in propellers for sea-going vessels; and it is to be hoped that skilful and judicious engineers will not dismiss the subject until their desired object is attained, and the government is in possession of an un-, exceptionable propeller for its steamships. *