Perry F. Nursey

“ If it is not of importance that the transparency of the glass should be preserved, no special precautions are taken to prevent the dust from the furnace settling on its face. Where, however, clearness is required, the glass is heated in a muffle, perfect transparency being obtained. The process of tempering or toughening, exclusive of the time required for heating the glass, occupies but a minute or so, the glass being immersed in the bath and at once withdrawn and set aside to cool. The cost per article, as may be supposed, is merely nominal. ”

“ As the skin of toughened glass can be cut through with the diamond, and as, moreover, its surface can be removed by polishing and cutting with the wheel, without injury to the mass, it is evident that it must exist under conditions very dissimilar from those of a Rupert's drop. Moreover, melted glass, on being dropped into De la Bastie's bath, gives a similarly shaped body, from which the tail can be broken off, piece by piece, without injury to the body, which can be scratched, knocked and thrown about, without exhibiting any signs of deterioration. ”

“ Many varieties of bronze have been produced within the last few years that possess features strongly distinguishing them from the ancient alloys, and some very remarkable qualities as compared with them, in view of which they are frequently used in place of even iron and steel, The bronzes of the ancients were composed of copper and tin, as is also what is now regarded as bronze pure and simple, mixed in proportions varying according to the purpose for which the compound is intended. ”

“ The castings of this metal are perfectly sound and homogeneous. Wherever strength, toughness, and durability are desired, phosphor-bronze is found to be better adapted than gun-metal and brass, and in many cases than iron and steel. Having the advantage of not becoming crystalline under the action of repeated shocks and bendings, it is well adapted for making wire-rope, and, not being acted upon by corrosive liquids or the atmosphere, its value as a metal remains constant. ”

“ Delta-metal in color resembles gold alloyed with silver. It can be worked hot and cold. When melted, it runs freely, and the castings produced from it are sound and of a fine, close grain. It can not be welded, but can be brazed, and, when of suitable thickness, "burned." The varieties designed for working hot are capable of being stamped or punched, similar to wrought-iron and steel, into a variety of articles which have hitherto been cast in bronze or brass. This property is of much importance, for the articles thus turned out are cheaper and stronger than brass-castings. ”

“ Watch-glasses, which perfectly retain their transparency, have resisted every attempt to break them by crushing between the fingers, or by throwing them about indiscriminately on the bare floor. Glass plates, dishes, colored lantern-glasses, and the like, have been similarly thrown about by the handful, stood upon, and otherwise maltreated, but without the slightest injury accruing to them, except, perhaps, when a solitary specimen which had been imperfectly tempered got in with the rest. ”

“ In the number one quality the zinc alloyed with the copper is considerably in excess of the tin. It may be worked hot or cold, and has great tensile strength and elasticity. Manganese-bronze number two is stronger, and can be cast in sand for special purposes where strength, hardness, and toughness are required; but it has to be melted in crucibles. One of its most important applications is to the production of articles cast in metal molds under pressure; and the articles thus made have the strength, toughness, and hardness of cast-steel, without any of its defects. ”

“ The action of phosphorus on copper alloys is principally due to its reducing qualities, by virtue of which the oxygen absorbed by the molten metal is removed, or the oxides formed thereby are eliminated, and the degree is imparted of homogeneity, strength, and toughness peculiar to the chemically pure metal. ”

“ But if toughened glass cannot be cut by the diamond, it can be readily cut and polished by the wheel, as for lustres and the like, so that wine-glasses and articles of cut glass-ware can be toughened directly they are made, and cut and polished subsequently. ”

“ Phosphor-bronze was first prepared by Dr. Kunzel, of Dresden, and was brought into practical use in England early in 1873. The alloys of this class are composed of copper, tin, and phosphorus, and other ingredients in variable proportions, and are made to be either as ductile as copper, as tough as iron, or as hard as steel, according as the proportions of the constituents are varied. The alloys used for rolling and drawing have very different proportions from those employed for castings, bearings, and parts of machinery. ”

“ The working oven, a, is heated by a furnace, b. The bottom of the oven, c, and the slope to the bath, are made in one piece of refractory material, and are very smooth on the surface. At the side of the oven is a preparatory oven, communicating by a passage in the separating wall. In this oven the glass is partially heated before being placed in the main oven, a. The products of combustion are carried away in the direction of the arrows through the chimney. When the oven, a, is sufficiently heated, the ash-pit and fire-doors are closed, and rendered air-tight by luting ”

“ What may be the ultimate result of the introduction of this invention in practice it is difficult to foresee, so wide-spread, so universal does its application seem. Not only is it desirable to render durable such articles as are at present made from glass, but to satisfy a want long felt in every department of art, science, and manufacture, of such a material as toughened glass ”

“ When the glass has been sufficiently heated, the workman, by means of a lever, tilts the table, and the glass slides gently down an easy incline on to a table set at a corresponding incline in the bath. ”

“ The history of the practical manufacture of aluminum does not extend very far back into the past; in fact, its commencement dates within the limits of the present generation. The three International Exhibitions which have been held in Paris since aluminum began to be worked on a commercial scale form so many landmarks in its progress. ”

“ They exist, in fact, in a state of compression, with but little mutual cohesion, and are only held together by the external skin. So long as the skin remains intact the tendency of the inner particles to expand and fill their proper space is checked and resisted by the superior compressive strain of the skin. ”

“ A fire-truck, p is charged with live fuel, heats the bath to the desired temperature. The glass is introduced into the preparatory oven by an opening in the outer wall, and thence it is moved through a second open-in on to the floor of the oven, a. ”