THE OBELISK OF LUXOR TO PARIS. d'appui to the lowering part of the appa ratus. On the opposite side, that is, on the side of the retaining apparatus RR, a point d'appui, of equal efficiency, was obtained in a much simpler and easier manner, by the engineer's availing himself of the base of the companion obelisk, in the manner represented at gg, figs. 1 and 3. All that now remained to be done in the way of preparation was to insert a block of oak, of a convex form at top, under the bottom of the wooden casing, on its smooth side, to serve as a sort of hinge on which the obelisk might turn in the course of its descent. To bring matters thus far, took three months and a half of constant labour and fatigue. Every thing being at last ready for lowering the obelisk, the cap stans, by which the lowering cable EF was to be worked, as well as the pulleys RR, by which the descent of the obelisk was to be checked and regulated, were fully manned, and the operation begun. In twenty-five minutes the obelisk had gained the position denoted by the dotted lines in fig. 1; it rested on the dwarf wall erected towards the right, forming an angle of about 20 degrees with the inclined plane. The whole apparatus creaked under the efforts of the two contending forces, but nothing gave 263 way. It became now necessary to poise the obelisk with great exactness on the wall which supported it, in order that it might be carried forward without slipping upon the trucks or trestles F. From the 31st Oct. to the 18th Nov. was occupied in this oscillatory process. Behold the monument at length safely deposited on the carriages destined to convey it on board. The face of the casing next the trucks had, as already mentioned, been well greased; so also were the trucks themselves, that every facility might be given to the passage of the immense load with which they were burdened, weighing, as it did, not less than 250,000 kil. (547,125 lbs. English, avoird.). These trucks were four in number, each composed (see fig. 5) of a solid plank, crossed by strong and well-secured girders, along which the obelisk slid. As soon as it had passed over one of them, that one was removed to the front, and so on successively. The distance which it had to travel down the inclined plane was 372 metres (about 1,500 English feet), and it took a month to accomplish the task, although the men laboured at it for fifteen hours a day. On the 19th of Dec. the head of the pyramid had arrived at the opening made for it in the ship. To understand the method adopted to introduce it on board, reference must be had to the engravings, figs. 9, 10, 11, 12. Fig. 9 is a section of the ship, near the bow, but with the immaterial parts of the interior hold omitted. Fig. 10, horizontal projection of the apparatus employed to embark the obelisk. Fig. 11, a section through the longitudinal plane of the ship. Fig. 12, a horizontal and vertical projection, which shows how the trucks were brought into the same line with the keelson of the vessel. In these four last figures: B represents the trucks; C the traction apparatus; D, capstans; E, cylinders to which the traction pulleys were fixed; F, a strong cable, which connected the obelisk with one of the cylinders E; G, two iron chains, which passed round the cylinder E; H, two holes made in the front of the vessel, to afford a passage to the chains G; JJ, anchors sunk in the ground at a little distance from the ship, and firmly secured there by weights and stakes to which anchors the chains G were fastened; K, a stone wall, constructed to prevent the chains from rub 264 RECENT AMERICAN PATENTS. bing against the ship; L, the keelson of the ship; N N O, the aperture made for the admission of the obelisk; P, the piece which was cut away; Q, the sheers which kept that piece suspended; T, props placed on each side of the obelisk to keep it in its proper position; U, abutment in front of the keel, constructed of stones and soft earth. These preparations for embarking the obelisk being all completed, the men were again set to work at the different capstans, and in two hours it was safely deposited on the keelson of the Luxor. From the 19th to the 25th of December was occupied in restoring the bow of the vessel to its place. She was then masted and rigged anew, disengaged from the sand in which she was embedded, and proceeded down the Nile on her way back to France. A view of the base of the obelisk is given at fig. 6. A slight fracture runs quite across it from V to V. To prevent it from increasing, two double-dovetailed tenons were inserted at the points X X. W. A. R. RECENT AMERICAN PATENTS. [Selected from the Franklin Journal.] IMPROVED WHEEL FOR LOCOMOTIVE CARS AND ENGINES. Ross Winans, C. E.. -The more clearly to exhibit the difference between this wheel and those which have been heretofore employed, it may be proper to point out the manner in which wheels for this purpose have been most commonly made. 1st. Such wheels have been made wholly, or nearly so, of cast iron; the face or tread of them being cast within a chill, consisting of a thick rim, or hoop, of iron, which forms a part of the mould. 2d. The wheels have been cast without being chilled, and afterwards hooped with wrought iron, which then forms the face and flanch of the wheel. 3d. A cast iron nave or hub, has been made to receive wooden spokes, inserted in wooden felloes, which were hooped with a tire of wrought iron. 4th. The hubs have been of cast iron, with spokes of wrought iron, and a rim of wrought or of cast iron, hooped with wrought iron. These plans have each their respective advantages and disadvantages, but neither of them has fully answered the purpose for which it has been adopted; the wrought iron hoop, or tire, upon the cast iron rims, have gradually become loosened; the wooden spokes and felloes have pressed the one into the other, and the tire has ceased to bind them, an evil which wedging will not cure. To remedy these defects, and others incident to some of the wheels, is the object of the present improvement. Mr. Winan's new wheel consists essentially of three parts, namely, an interior wheel, the hub, spokes, and rim of which are of cast iron; a rim of wood, formed in a way to be presently described, surrounding the cast iron wheel; a hoop, or tire, of wrought iron, surrounding the wood, and forming the face or tread of the wheel. The inner wheel is made, in some respects, like those first noticed, but the face is not chilled, nor has it the same form with the chilled face. It should be made of the same width on the rim with the wrought iron tire which is to surround and form the tread of the wheel, say five inches. The face of the cast rim may be cylindrical for the greater part of its width, but it must in this case have a fillet, or edge, projecting up on each side of it, say to the height and of the thickness of half an inch, which will then give to it the appearance of a wheel with a double flanch, having a cylindrical tread of four inches in width. Instead of making the face in this form, the patentee proposes sometimes to give to it a regular declination from each edge towards the centre. A section of the rim, transversely, would then be somewhat in the form. of the letter V, but with the angle obtuse. The inclination will be sufficient if the diameter at the centre of the rim is one inch less than at the sides or edges. Other forms may be given to the face of the rim, by which the object in view may be attained, namely, that of retaining the wooden rim in its place, without its allowing it to move out on either side. A rim of wood is to be placed around this wheel, which may consist of any convenient number of pieces, fitted to each other and to the face of the wheel. The grain of the wood is to cross the rim of the wheel, running parallel with its axis. These pieces may be fitted to the face of the wheel with great facility, by driving them into a large hoop, running as a chuck in a lathe, by which means they may be turned to the form required; they may then be fastened on to the rim by wood screws, or otherwise, and turned thereon to receive the iron hoop or tire. The best thickness of this rim will be from two to four inches. The hoop, or tire, of wrought iron, is to be made in the usual form, turned truly, and passed on over the wooden rim when expanded by heating it as highly as may be done without burning the wood. Bolts are then to be passed the wrought iron, the wood, and the cast iro rims, which are secured by nuts, to confine the whole together." The hub, or nave, in a wheel thus mide, may be cast entire, instead of having those VALUE AND IMPORTANCE OF MATHEMATICAL SCIENCE. divisions or openings which are necessary in the chilled wheel, to allow for contraction. It will be readily perceived that the wood, thus pressed between two hoops of iron, has an extent of bearing surface which will effectually prevent its being condensed by the force to which it is subjected; whilst, by its elasticity, it will tend to preserve both the road and the vehicles passing over it. If perfectly dried when put on, which may be done by artificial heat, the wood will never shrink, but, on the contrary, will expand, and render all the parts the more firm. Such a wheel will have less tendency than any other, where wood is employed, to get out of truth; and should wedging become necessary, it may be done more effectually than with any other. The dimensions of most of the parts of such a wheel need not differ greatly from those of the cast iron wheels with chilled rims, but, like them, must vary according to their diameter, and the load they are to sustain; the following is a good proportion for wheels of three feet in diameter; intended for cars carrying threee tons:-Cast iron interior wheel, twenty-nine inches diameter; hub seven inches long by six in diameter, spokes, twelve in number, five-eighths of an inch thick, and three and a half or four inches broad; rim five inches broad by five-eighths of an inch thick; wooden rim two and five-eighths inches thick, five inches deep, measuring across the rim; wrought iron tire seven eighths of an inch thick, five inches broad; flanch one and one-fourth inch deep one inch thick. A TENONING MACHINE. Henry Mellish. -Two iron wheels, or disks, are fixed upon a vertical shaft, made to revolve by a band passing round a pulley; the iron disks are placed at a distance from each other exceeding that of the thickness of the tenon to be cut. Upon the peripheries of the wheels are placed chisels or cutters; and the pieces of timber to be tenoned are secured by proper contrivances, upon a sliding carriage, so that the stuff can be brought up against the revolving cutters, which leave the tenon of the right thickness, and properly shouldered, when it has passed through the revolving disks. ON THE COMPARATIVE VALUE AND IMPORTANCE OF MATHEMATICAL SCIENCE, AND ON THE PRETENSIONS OF ITS PROFESSORS. Sir, Whilst occupied in writing a reply to Kinclaven, I was led to indulge in some observations on the intellectual grade and practical value which ought to be assigned to mathematical acquirements, and on the overweening pretens 265 sions of some of the mathematicians; but these remarks became so much extended under my hand, that I have thought it best to give them to you under another formi. I am, Sir, Yours respectfully, BENJ. CHEVERTON. Men's minds appear to be differently constituted in regard to the investigation of things. Whilst the generality take a view of a subject merely as a particular case, and reason upon and examine it only as connected with its more immediate causes and consequences, the profound inquirer analyses it, to discover the law or principle which pervades it in common with many others; to trace and connect it with those of dissimilar aspect; to show that in the abstract they belong to one common truth, though in the concrete, or in their actual existence, produced by the modifying agencies of their peculiar circumstances, they present appearances which apparently have no relation to each other. Such are the minds who have for their high aim the extension of the principles of knowledge; but though peculiarly fitted for discovery, they are not the best qualified to bring science down to practical application, or even to make it literally accord with matter of fact. In disentangling the complications resulting from concomitant agencies, they are so intent on arriving at the most general truths, so systematically disregardful of the separate consideration of those agencies, and so much in the habit of keeping the analysis disencumbered of all ideas not comprised in the upward leading train, that when, by a course of synthetical reasoning, they would turn their discovered principles to account, and build up a system on their foundation, they too much exclude the operation of the subordinate laws which concur in influencing, and more immediately regulate, the ultimate result, and which give to things the form and appearance which they present. Their conclusions, though correctly drawn are true only in part, and by assumption and limitation, true mentally, but not materially, or as found in actual existence. But there is another class of minds of nearly the same stamp and mould as the former, who, though not taking the like 266 VALUE AND IMPORTANCE OF MATHEMATICAL SCIENCE, grand and original views, are yet of a kindred spirit. The former act the part of pioneers, but these take to the circumstantials, and bring into subjection what the others merely pass by. They fill up that outline of a science or system which the former, in the discovery of its most general law, was content merely to trace; they bring the analysis to bear on all the relations implicated; weigh, balance, and proportion the conflicting agencies; and are thus enabled to perfect the subsequent synthesis in all its details; to take a complete view of the subject in all its parts, and a comprehensive one in all its bearings, and to bring forth to view the modified results, the exceptions and the anomalies, as illustrations of, and confirming attestations to the fundamental truths which, at first sight, they may appear to invalidate. Both these classes of men are philosophers, the distinction between them having reference to a tendency to generalise, rather than to the usefulness of their labours, or the rank in which they ought to stand; but they may not be mathematicians, that depending on the circumstance whether the science of quantity is required in their investigations. These last, therefore, form a third class, whose object is less the extension and perfection of science or system, than the cultivation of the means thereof, so far as the relations of quantity are concerned. The mathematicians-I mean mere mathematicians-are doubtless valuable members of the body scientific, but some among them (the least generally informed) are sadly inclined to over-estimate the honour of their station, and the comparative value and importance of their labours. In the great field of science, to say nothing of the greater field of knowledge, they occupy merely one of its sections, they facilitate and abridge the work of some, and co-operate in the work of others; but they are neither the pioneers nor the finishers of the operations going on around. Subsidiary and assistant to original investigation, the science of quantity is of important service, but if put forward and esteemed as the science of things, it is worse than useless, and many who might have made good philosophers, have been spoiled by the false glare reflected from their own doings being taken for the true light thrown on nature's works. The lines and characters with which mathematical operations are conducted, and whose results, though only abstractions, are too often confounded and identified with realities, are not only the mere symbols of things, but the symbols merely of one or two qualities in things; and, therefore, though the conclusions are true, rigorously true as to the signs, they are false as to the things themselves, when regarded in their ultimate modified results, from the influence of those qualities or accidents which the mathematician does not or cannot symbolise-which he does not, because the complication arising from their reciprocal actions exceeds and defies his means-which he cannot, because in regard to some of them, there is not sufficient analogy in the types to warrant the deductions they afford being transferred to the archetypes. Even as to those said qualities (extension and individuality) which form the subject matter of mathematics, the investigation is often limited, and therefore imperfect, from the impossibility of extending the analysis to all the ramifications which branch forth from it. The mathematician arrives at the truth, and nothing but the truth, but not at the whole truthnot even at the whole of the only kind of truth which symbols give. When, however, the case is so simple that the investigation comprehends all the possible relations belonging to those qualities, and the only result sought for in things is a knowledge of those relations, then it may be said, and only then, that the conclusions of the science are not only indubitable, but identical with realities-but what does not this limitation exclude? The mathematician has a little, a very little, world of his own, in which every thing is in the utmost order, subject to known laws, involving definite and foreseen action, liable to no interference not calculated on and provided for, and the whole capable of coming within his own powers to regulate and govern according to assigned rules; for things which can not be made amenable to his jurisdiction are ejected from his domain. He therefore admits nothing of unknown power or which may exert an influence, which he cannot see, and introduce uncertainty and casualty within his precincts. Hence, also, many agencies, though well understood, are rejected by him, lest they should prove too numerous for his perfect |