Metal Founding.—The treatment of metal after it flows from the furnaces, or is poured from the crucibles into moulds, by the operations of facing, drying, covering, casting and stripping, has given rise to a multitude of machines and methods for casting a great variety of objects. The most interesting inventions in this class have for their object the chilling, or chill hardening, of the outer surfaces of articles which are subject to the most and hardest wear, as axle boxes, hammers, anvils, etc., which is effected by exposing the red-hot metal to a blast of cold air, or by introducing a piece of iron into a mould containing the molten metal.
In casting steel ingots, in order to produce a uniform compact structure, Giers of England invented “soaking pits of sand” into which the ingot from the mould is placed and then covered, so that the heat radiating outward re-heats the exterior, and the ingot is then rolled without re-heating.
Sheet Metal Ware.—Important improvements have been made in this line. Wonderful machines have been made which, receiving within them a piece of flat metal, will, by a single blow of a plunger in a die, stamp out a metal can or box with tightly closed seams, and all ready for the cover, which is made in another similar machine; or by which an endless chain of cans are carried into a machine and there automatically soldered at their seams; and another which solders the heads on filled cans as fast as they can be fed into the machine.
Metal Personal Ware.—Buckles, clasps, hooks and eyelets, shanked buttons, and similar objects are now stamped up and out, without more manual labour than is necessary to supply the machines with the metal, and to take care of the completed articles.
Wire Working.—Not only unsightly but useful barbed wire fences, and the most ornamental wire work and netting for many purposes, such as fences, screens, cages, etc., are now made by ingenious machines, and not by hand tools.
In stepping into some one of the great modern works where varied industries are carried on under one general management, one cannot help realising the vast difference between old systems and the new. In one portion of the establishment the crude ores are received and smelted and treated, with a small force and with ease, until the polished metal is complete and ready for manipulation in the manufacture of a hundred different objects. In another part ponderous or smaller lathes and planing machines are turning forth many varied forms; in quiet corners the boring, drilling, and riveting machines are doing their work without the clang of hammers; in another, an apparently young student is conducting the scientific operation of coating or gilding metals; in another, girls may be seen with light machines, stamping, or burnishing, or assembling the different parts of finished metal ware; and the motive power of all this is the silent but all-powerful electric current received from the smooth-running dynamo giant who works with vast but unseen energy in a den by himself, not a smoky or a dingy den, but light, clean, polished, and beautiful as the workshop of a god.
[CHAPTER XVI.]
ORDNANCE, ARMS AND EXPLOSIVES.
Although the progress in the invention of fire-arms of all descriptions seems slow during the ages preceding the 19th century, yet it will be found on investigation that no art progressed faster. No other art was spurred to activity by such strong incentives, and none received the same encouragement and reward for its development. The art of war was the trade of kings and princes, and princely was the reward to the subject who was the first to invent the most destructive weapon. Under such high patronage most of the ideas and principles of ordnance now prevailing were discovered or suggested, but were embodied for the most part in rude and inefficient contrivances.