The London Indisputable Life Policy Company. INCORPORATED BY ACT OF PARLIAMENT. No. 31, LOMBARD-STREET, LONDON. TRUSTEES. J. Campbell Renton, Esq., M.D. Richard Malins, Esq., Q.C. Richard Spooner, Esq., M.P. James Fuller Madox, Esq. William Wilberforce, Esq. DIRECTORS. William Adams, Esq. AUDITORS. George Cumming, Esq. Samuel Field, Esq. William Ghrimes Kell, Esq. MEDICAL ADVISER. Benjamin Phillips, Esq., F.R.S. BANKERS. Messrs. Spooner, Attwood, and Co. SOLICITORS. Messrs. Atkins and Andrew. SECRETARY. David Alison, Esq. The POLICIES are INDEFEASIBLE and INDISPUTABLE, which renders them certain as Family provisions, and negotiable instruments of security for pecuniary transactions. To remove all doubt upon this important subject, at present, and for all future time, the following clause has been inserted in the Deed of Incorporation of the Company; Clause 84. "That every Policy issued by the Company shall be indefeasible and indisputable, and that the fact of issuing the same shall be conclusive evidence of the validity of the Policy, and it shall not be lawful for the Company to delay payment of the money assured thereby on the ground of any error, mistake or omission, however important, made by or on the part of the person or persons effecting such Assurance, and that on the contrary, the amount so assured shall be paid at the time stipulated by the Policy, as if so much error, mistake or omission had been made or discovered." The whole Profits belonging to the Assured. ALEXANDER ROBERTSON, Manager. To Engineers and Boiler THE BIRMINGHAM PATENT IRON tube COMPANY Manufacture Patent Lap Welded Tubes, under Mr. Richard Prosser's Patent, for Marine, Locomotive and all Tubular Boilers. Also Tubes for Gas, Steam, and other purposes, All sorts of Iron Gas Fittings. Works, Smethwick, near Birmingham, London Warehouse, 68, Upper Thames street. A stamped edition of the Mechanics' Magazine, to go by post, price 4d., is published every Friday, at 4 o'clock, p.m., precisely, and contains the substance of all the Specifications Enrolled, all the New Patents sealed, and all the Articles of Utility registered during each week. Subscriptions to be paid in advance. Per annum 17s. 4d., half-yearly Ss. 8d., quarterly 48. 4d. Erratum.-Page 66, col. 1, line 9, from bottom, for "sulphur" read "saltpetre." NOTICES TO CORRESPONDENTS. LAW OF PATENTS. THE REPORT OF THE ROYAL COMMISSION ON THE SIGNET AND PRIVY SEAL OFFICES, has been published too late in the week to allow us to do more than print a portion of it in our present Number. In our next we shall give the remainder of it; and in succeeding Numbers, the principal portions of the evidence. Several communications of importance are unavoidably deferred. The Supplement to our last Volume, containing Titles, Indexes, &c., will be published on the 1st of August. MUSEUM, REGISTER, JOURNAL, AND GAZETTE. No. 1356.] SATURDAY, AUGUST 4, 1849. [Price 3d., Stamped, 4d. Edited by J. C. Robertson, 166, Fleet-street. MR. BESSEMER'S FURTHER IMPROVEMENTS IN THE MANUFACTURE OF GLASS. Fig. 6. Fig. 4. MR. BESSEMER'S FURTHER IMPROVEMENTS IN THE MANUFACTURE OF GLASS. (Patent dated January 31, 1848. Specification enrolled July 31, 1848.) THE manufacture of glass makes slower progress in this country, than was anticipated from the repeal of the duties, by which it was so long fettered and obstructed. We ought to be able to make anything in glass which is made in metal; so strong, indeed, is this impression among the glass-makers themselves that they are in the habit of calling glass itself a metal; but we are still very far from having arrived at such a consummation. There are a great many articles still made in silver, brass, iron, &c., as well as other substances, for which glass would be much preferable. We might fill columns with instances of this, but we refrain from doing so, lest we should forestall the labours of any inventor whose ingenuity may be applying itself in this direction. Another circumstance worthy of note is, that such improvements as have been made since the repeal of the duties, have emanated chiefly from amateurs or persons not practically engaged in the manufacture of glass. The workers in glass themselves have done but little. Among these amateurs none has so distinguished himself as Mr. Bessemer, of whose previous successful labours in this department of art, the reader will find some account in our xxxvii. vol., p. 98. Mr. Bessemer's present patent has reference chiefly to plate glass, and is prefaced by an exposition of defects in the existing system of manufacture, which is quite startling for the amount of vulgar error and ignorant practice which it displays. Whereas the ordinary casting table consists generally of a large plate of cast iron, from 12 to 15 feet in length, 5 to 7 feet in width, and from 4 to 6 inches in thickness, more or less, which is placed either on a bed of masonry or on a frame with wheels, and is planed to a true level on the upper or casting surface; and whereas, in order to cast plates of glass perfectly flat and of one uniform thickness, it is necessary that the table should maintain throughout the operation of successive castings, the same true plane as at first; but this is prevented by the unequal expansion of the iron; for as soon as the liquid glass is poured upon it, the upper surface of the thick table absorbs heat therefrom, and becomes expanded more than the under surface, producing thereby a slight curvature of the table, which curvature becomes greater and greater with the addition of each successive potful of glass. Again; the ordinary casting table is placed in a horizontal position, and the plate of cast or rolled glass has to be removed from it while in a soft state, and the force required to slide it off the table renders it necessary, that the end of the plate should be folded up, and a sort of peel or pusher placed within the folded portion, by which means the soft plate is made to move in the required direction, the folded portion going foremost. Although this causes a waste of the folded part, it is rendered necessary, by reason of the weight of the plate being too great to be pushed from behind edgewise on a horizontal plane, without putting it out of shape. Moreover, in the ordinary mode of casting on a table, the large roller which is passed over the glass to form it into a plate, is either allowed to fall down on a trestle when it arrives at the end of the table, or is removed on a frame with wheels; in either of which cases an interval is left between the end of the casting table and the mouth of the annealing kiln, equal to the diameter of the roller, which interval has to be filled up by a boarded or other surface, over which the soft glass is pushed into the oven; or the plate of glass is put upon a wooden truck, . and wheeled by the workmen to the mouth of the annealing kiln. And whereas also kilns have for a long time been in use for annealing plate or cast glass, having the bottom, or floor, formed with fire-tiles laid on sand, and it is frequently necessary to employ a workman to get into the kilns to re-adjust the tiles; nevertheless the general surface they present is neither flat nor uniform, and as the soft sheet of glass takes an impress of the irregular surface on which it is laid, it thereby requires much more grinding before it can be reduced to a true plane; besides which, it has to be made much thicker than is ultimately required, in order to compensate for the loss in grinding. Again; the arched roof or crown of such kilns is generally very thick, and covered over with sand or other bad conductor of heat: the consequence of which is that they cool very slowly, that several days are ordinarily occupied in the annealing process, and thus a great many more kilns are necessary than would be required if the kilns were cooled down more quickly. In the ordinary kilns, too, the heat is derived from one or more furnaces in immediate connection therewith, and a flue, or flues, leading therefrom. By this mode of heating it is not possible to get an equal temperature at all parts of the kiln, since those parts nearest the furnaces will receive much more heat than the more distant ones; and when the kiln is closed currents of air are sure to traverse the kiln and flues, unless all the inlets and outlets are made absolutely air-tight, which currents must have the effect of causing an unequal cooling of the plates of glass within them. Farther, as the flame plays through the kiln, soot and dust, or fire-ashes, will accumulate therein, and add to the inequalities of the floor, arising from the other causes aforesaid. Mr. Bessemer's improvements embrace remedies for the whole of the defects thus pointed out; and the nature of each will be gathered from the claims which we give in full at the end of this notice. We select for present illustration the first, second, and eighth heads, and shall in a future Number give the particulars of two or three of the others. First Head. The first head includes a new description of casting table, the peculiar features of which are, that it is planed true on both sides, and turns on trunnions, to a chain, which pins pass through the side piece, a, and into holes made in the edge of the table to receive them. Both surfaces of the table, ff, are to be planed true and level. The roller and guides, as well as the "tangs", or bars for determining the thickness of the plate, may be made and used in the ordinary way. When it is desired to cast or roll the contents of several pots of glass, the pins, ii, are inserted through the frame, in order to keep the table steady. The casting may then be proceeded with; and as soon as the plate of glass is removed from the top surface of the table, the pins, ii, are to be withdrawn, and the table moved upon its trunnions until the under surface becomes uppermost, when the pins, ii, are again to be inserted, and the casting of another plate of glass proceeded with. As soon as the second potful of melted glass is poured on to the table, the expansion of the surface in contact with the glass tends to neutralize the warping caused by the former operation, and by the amount of expansion being equalized on both sides, not only is the flatness of the table preserved, but its liability to crack is greatly diminished. In continuing the casting operation, the two sides of the table are to be used in regular succession. A hollow place must be made in the floor beneath the table, in order to allow it to turn round. The dotted lines, j, show the position which the table will assume at a particular part of a revolution on its trunnions. Second Head. Secondly. My invention consists in mounting such casting tables as are intended to be used on one side only, in such bearings and in such manner that the plates of glass may be moved from them at once into the kiln or oven without having to pass over any intermediate surface, and without requiring the end of the plate to be folded up as heretofore. Figure 3, is a side elevation of a table so constructed; fig. 4, an end elevation, with part of the framing, n, and some other pieces left out for the sake of showing the other parts more clearly; and fig. 5 is a longitudinal section taken through the centre of this apparatus. The framing of the table consists of two side pieces, m m, which are secured by cross pieces. The table, o, which is in this case formed of a large plate of iron, planed flat on its upper surface, is supported on trunnion pins, p, which project from each side of it, and rest in hollows, m*, formed in the side pieces. On the under side of the table there are two levers, rr, which move in joint pieces, ss, which are secured by bolts to the table. On the lower edge of the side frames there are projections, q, into which the way-shaft, 1, works at both ends. Levers, u u, are keyed at their lower ends on to the way-shaft, t, and the upper end, which is forked, is jointed to the levers, r r. When these levers, rr, and u u, are both in a vertical line, as represented in fig. 3, they form a support for the table. In order to change the horizontal position of the table, as shown in fig. 3, to the inclined position shown in fig. 5, it is necessary to cause the levers, r and u, to deviate from the vertical line, and for this purpose another lever, w, is keyed on the centre of the shaft, t, to which lever is attached by a joint the connecting-rod, x, the other end of which is jointed to the bent lever, y, which moves on a joint made in the angular piece of iron, z, which is bolted to the table. To give the table the inclination shown in fig. 5, the handle, y*, is to be pulled upwards, and its bent end acting on the rod, x, will cause the levers, uu and w, to move on their axes, t, carrying with them the lower ends of the levers, rr, and thereby causing the end of the table, o*, to sink down until it rests on the ends of the adjusting screws, AA, one of which passes through projections, B, cast on both the side pieces, mm. CC represents a section of the portion of the floor of an annealing kiln, having a large block of stone or fire lump, D, partly projecting outwards from the mouth of the oven. E is the roof, and F the front wall, which is supported by a large plate or girder of iron, G, with a flange at G*, which extends entirely across the oven, and rests on the side walls. At the lower side of this girder, G, there is a narrow flap or door, Q, which extends across the oven, and closes the wide opening through which the plate of glass is pushed into the oven. The girder, G, has two iron brackets, H, securely bolted to it, and of such height above the table that the long projecting axis, II, of the roller, J, may pass on to and rest upon these brackets. When the roller is moved to the end of the table, O*, the casting table is brought into its required place in front of the annealing oven by moving on flanged wheels, Kk, which run on two lines of sunk rails, LL. These wheels are supported in iron frames, NN, which extend across the lower rail of the framing, and are bolted to the side pieces, m. When the operation of casting is to be performed, the table is wheeled to the front of the oven in which the plate is to be annealed; and the screws, M M, which pass through projections, P P, formed on the side frames, m, are turned so as to give a firm support to that end of the table. The roller used to form the plate of glass is then |