Important: Safety Warning
This page describes trade processes that use dangerously toxic materials such as cyanide solutions, mercury amalgams, or strong acids. These processes require training, equipment, and precautions far beyond what the text describes.
This information has been left in for historical purposes but should not be acted upon.
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Mackenzie Blower
The fan-blades in this blower are supported by a shaft, and caused to revolve by the revolutions of a cylinder contained in the shell. The…
Mackenzie Cupola
The Mackenzie cupola has a continuous tuyere, which allows the blast to enter the fuel at all points. Each size is proportioned to melt a…
Magnet
There are two kinds of magnets-natural and artificial. The natural magnet is an iron ore which has the property of attracting to itself…
Malachite
A mineral, the green carbonate of copper; also called velvet copper ore. It is much admired as an ornamental stone for inlaying purposes…
Malleability
A property possessed by metals which renders them capable of being beaten out with a hammer or pressed into plates between rollers. Gold…
Malleable Bronze
Hard bronze may be made malleable by the addition of from 1/2 to 2 per cent mercury, which may be combined with either of the metals…
Malleable Iron
By depriving cast iron of a portion of its carbon it may be converted into malleable or wrought iron, becoming ductile and tenacious, and…
Mallet
A wooden hammer for service in the foundry, where the marks produced by the smaller iron-faced hammer is objectionable. Besides the…
Manganese-bronze
This bronze, manufactured by P. M. Parsons, England, for every purpose for which gun-metal has heretofore been employed, and for which…
Manheim Gold
A brass imitation of gold, composed of copper 16, zinc 4, and tin 1. To insure close resemblance to gold, the crucible must be clean…
Manure
See LOAM; HORSE-MANURE. Marble is a rock belonging to the varieties of carbonate of lime which have a granular and crystalline texture. It…
Marble-chips
The chips from a marble-yard are the very best material to use as a limestone-flux in cupolas, being comparatively free from the…
Match-board
Same as match-plate, except that it is made of wood instead of metal. See MATCH-PLATE; MATCH-PART. Match-part, sometimes called a "sand…
Match-plate
A plate provided with pin-holes corresponding to pins and holes of the top and bottom flasks between which it is placed, to be rammed on…
Maul
A heavy wooden sledge-hammer, useful in the foundry for many purposes for which iron ones are objectionable. They are especially effective…
Medals
If it is desired to obtain a convex and a concave plaster-mould from a medal, press tin-foil close into every part of the surface and pour…
Melting-furnace
The cupola and reverberatory are the iron-foundry melting-furnaces; the crucible air-furnace, forced-draught, and reverberatory are the…
Melting-point
The exact amount of heat at which metals and other substances become fused and lose their identity. (See FUSIBILITY.) The following gives…
Mending-up
The art of repairing broken surfaces in the mould which may have been caused by accident, carelessness, or faulty models or patterns. This…
Metallurgy
In a limited sense metallurgy includes only the operations attendant on the separation of metals from their ores; but it really comprehends…
Metals
There are three states in which metals occur in nature. First, some of them, as gold, silver, platinum, and mercury, are frequently found…
Meteoric Steel
Steel resembling the famed Damascus steel is made by melting in a plumbago crucible, well covered with charcoal, silver 4, nickel 16, zinc…
Meteoric Stones
Usually called aerolites, fire-balls, or shooting-stars, which occasionally fall from the atmosphere. When taken up soon after their fall…
Metre
A measure of length equal to 39.370 English inches, or 39.368 American inches, the standard of linear measure, intended to be the…
Metric System
The metric system of weights and measures was first adopted in France, and by Act of Congress was authorized to be used in this country…
Mica
A mineral of a somewhat metallic lustre, that will permit of being split in thin plates, which can be substituted for glass in ship's…
Mill-cinder
The slag produced at the reheating and puddling furnaces. This slag, after several days' roasting, becomes highly refractory, and is known…
Mineral Cotton
If a jet of steam is forced through liquid slag, the latter is changed into a mass of fine white threads, which when gathered together…
Mineralogy
The science which treats of the solid and inanimate materials of which our globe consists, the four classes of which are earthy minerals…
Mineral Oils
See PETROLEUM. Minerals are all such natural bodies as are destitute of organization, existing either within or on the surface of the…
Mitis Metal
The name given to an alloy of aluminum with wrought iron. For the production of castings in this metal, the wrought iron is heated until it…
Mixing Cast Iron
The art of mixing certain proportions of different brands of iron to obtain castings of such quality as will best serve the purpose for…
Mock Platinum
A factitious platinum is produced by mixing 5 zinc with 8 brass. For composition of brass, see BRASS. Mock Silver is a white-metal alloy…
Modelling
The art of designing or copying works of art in clay, for the purpose of obtaining moulds in which they may be cast in plaster or metal…
Modelling-clay
Common potters'-clay mixed with water will answer for inferior work; for work of superior quality dry clay may be brought to the right…
Moire Metallique
A crystalline appearance of great beauty given to tin-plate by brushing over the heated metal a mixture of 2 parts of nitric acid, 2 of…
Molasses
A brown, viscid, uncrystallized syrup produced in the manufacture of sugar. Owing principally to the gluey nature of this product, it can…
Molecule
One of the constituent particles of bodies. The molecules of bodies are divided into integrant and constituent, the integrant having…
Mosaic Gold
A cheap brass used for making imitation jewelry. It is made by alloying copper with about equal parts of zinc. See GOLD ALLOY; ORMOLU…
Mottled Iron
The variety of pig iron which is evidently between the two extremes of white and gray. The fracture shows a decided mottle, seemingly…
Moulding
The art of preparing moulds from plastic materials of such a nature as will successfully resist the intense heat of molten metal,--as loam…
Moulding-machines
These machines, in infinite variety, are now recognized everywhere as competent to produce castings of limited variety, in a far superior…
Moulding-sand
See FACING-SAND. Moulding-tools.-Broadly speaking, moulding-tools consist of every foundry equipment necessary to make moulds with…
Magnesian Limestone – Moulds, Open-sand
See MAGNESIUM. Conchoidal bog-iron ore. See BOG-IRON ORE.
Muck-bar
When the iron has been balled in the puddling-furnace, forced through the squeezer, and passed once through the roughing-rolls, it is…
Muffle
An arched vessel with a flat bottom, made of refractory materials, in which to place cupels and tests in the operations of assaying, to…
Muntz-metal
An alloy of copper and zinc used for the sheathing of ships, composed of copper 60, zinc 40. This alloy admits of hot rolling. See BRASS…
Mousing-hook, Mushet's Crucibles & Music-metal
A hook with some contrivance for preventing the hook, ring, or link resting therein from slipping out. See CRUCIBLES.