The historical development of the horseshoe in general, from about the time of Emperor Maximilian until the seven years war, furnishes a true picture of the confused condition of things at that period of time, which, to make intelligible, would require a separate and complete treatise. Interesting as it is to the scientist to follow up this development and mode of present German horseshoeing, which, aside from the national toe and calk, is the English form and has become influential, and with full right, for a periodical of this kind further, more comprehensive, statement would under all circumstances take up too much room; therefore I must drop the pen, although reluctantly.
[Illustration: FIG. 23.]
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SHEET GLASS FROM MOLTEN METAL.
The present practice in making metal sheets is to cast ingots or slabs and then reduce these by repeated rollings and reheating. Attempts have been previously made to produce sheets directly from molten metal by pouring the metal: (1) between two revolving rollers; or (2) between a revolving wheel and the surface of an inclosing fixed semicircular segment. By these means none but very thin plates could be satisfactorily produced. In this invention by C.M. Pielsticker, London, the machinery consists of a large receiving roller of 5 ft. diameter more or less, and of a length equal to that of the plate to be produced. With this are combined small forming rollers arranged in succession part way round the periphery of the large roller, and revolving at the same rate as the large roller. The rollers can be cooled by a current of water circulating through them. The molten metal flows on to the surface of the large roller and is prevented from escaping sideways by flanges with which the large roller is provided. These flanges embrace the small rollers and are of a depth greater than that of the thickest plate which it is proposed to roll. The distance between the large roller and the small rollers can be adjusted according to the desired thickness of the plate. When dealing with metals of high melting point, such as steel, the first small roller is made of refractory material and is heated from inside by the flame of a blow pipe. The rollers are coated with plumbago or other material to prevent adhesion to the molten metal. In the case of metals of high melting point the machine is fed direct from a furnace divided into two compartments by a wall or bridge in which is a stopper which can be operated so as to regulate the flow of metal. When applied to forming sheets of glass, the rollers should be warmed by a blow pipe flame as above described, and the sheet of glass stretched and annealed as it leaves the last roller.
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WELDLESS STEEL CHAINS.
At the Royal Naval Exhibition, London, Messrs. William Reid & Co. are exhibiting their weldless steel chains, which we now illustrate.