G
Gagger
A turned piece of rod iron for binding the surface sand firmly to the cope. If the surface below the joint extends but a little way, a…
Gannister
A highly refractory siliceous rock, used very extensively in the several processes connected with the manufacture of steel and in the…
Gas
A name given to all permanently elastic fluids and airs. Gases have no cohesion, in consequence of which, their particles tend to recede…
Gas-blast Furnace
The only prerequisite demanded for the gas-blast furnace, manufactured by the American Gas Furnace Company, is a positive air-pressure…
Gas-house Coke
This class of coke is invariably unfit for cupola purposes, because it has not sufficient cohesiveness to sustain the weight of the charges…
Gate
That part of a system of runners which is in direct contact with the casting. In a plain mould, consisting of a cope and nowel, containing…
Gate-pin
An upright runner (round, square, or flat) which is rammed up vertically in the cope, and forms the connection betwixt the orifice for…
Gate-rake
A strong, four-pronged steel fork for lifting the gates and medium heavy scrap out of the sand in the scrap-pile. The prongs are wide apart…
Gate-spool
An inverted cone, usually made of wood, and turned smooth, with a handle projecting from its base. It is used for pressing back the sand…
Gauge-stick
A fixed measure employed by a loam-moulder. One edge is straight; its full length represents outside diameter, and notches indicate the…
Geared Ladle
A pouring ladle provided with mechanism for tipping, invented by James Nasmyth, England. Makers of geared ladles, now very numerous, mount…
German-silver
An alloy deriving its name from the circumstance of its being first made at Hildesheim, Germany. It is a useful silver-like alloy, composed…
Gilding
The three methods of gilding are: mechanical, chemical, and encaustic. Picture-frames, etc., are first oiled and then coated with whiting…
Glucinum
A metal resembling aluminum, prepared after the same manner. It is rare metal, and was discovered by Wohler, 1828. See ALUMINUM. Glue is an…
Glue Moulds
Plaster casts of intricate objects may be obtained by making the mould of glue. Bunches of grapes, etc., for instance, are taken in their…
Gold Alloy
An imitation resembling the pure metal in color and of about the same specific gravity is made by melting together in a crucible, well…
Gold-solder
Take gold of the same quality as the article to be soldered, and add 1/12 of silver and 1/24 of copper. A larger proportion of silver and…
Grades of Pig-iron
Pig-iron produced from the same ores differs in its nature and quality, and must be rated or graded in such a manner as will indicate the…
Grain-tin
See TIN. Granite is a widely known igneous rock, composed of quartz, feldspar, and mica, united in a confused crystallization. Feldspar…
Graphite
The nature of graphite, sometimes called plumbago or black lead, is not generally understood. Eminent writers on friction have declared…
Gravity
See SPECIFIC GRAVITY. Gray Pig-iron is all pig-iron that contains a large proportion of its carbon in a graphitic state. Such irons may be…
Green-sand Core
The inner mould, whose outside surface has been fashioned to correspond with the desired form of the inside of a casting, and which has…
Greiner Patent Cupola
This remarkable cupola is thus described by the patentee: "The novelty of the invention consists in a judicious admission of blast into the…
Grouting
The process of pouring a thin mixture of kaolin or fire-clay betwixt the cupola shell and the fire-bricks, as well as at the joints of the…
Gudgeon
The cast or wrought iron journal-piece inserted in the ends of a core-barrel, forming a horizontal shaft or axle, with collars for turning…
Gems, Imitation – Gun Resins
See PASTE GEMS. A beautiful white alloy for table-ware, etc. Its composition is: copper 1, antimony 4, tin 48. See GERMAN-SILVER; WHITE…
Gun-metal
A soft gun-metal that will bear drifting is made from: copper 16, tin 1. Harder, for heavy guns: copper 9, tin 1. A small proportion of…