. The pictorial sketch-book of Pennsylvania, or, Its scenery, internal improvements, resources, and agriculture, populary described . heavy and improvedmachinery. Wire as thick as an ordinary ram-rod is crimped by thisprocess, which merely consists of a heavy hammer, suspended inframe-work, which is made to fall upon the wire, placed under it,upon a surface allowing it to receive the particular hend desired, afterwhich it is woven into frames of about three feet square. Theseframes are then placed over a large wooden cylinder, and rounded,when two or more sections are pointed and riveted toget
. The pictorial sketch-book of Pennsylvania, or, Its scenery, internal improvements, resources, and agriculture, populary described . heavy and improvedmachinery. Wire as thick as an ordinary ram-rod is crimped by thisprocess, which merely consists of a heavy hammer, suspended inframe-work, which is made to fall upon the wire, placed under it,upon a surface allowing it to receive the particular hend desired, afterwhich it is woven into frames of about three feet square. Theseframes are then placed over a large wooden cylinder, and rounded,when two or more sections are pointed and riveted together, whichcompletes their circular form. The screen, thus complete, is removed ANTHRACITE COAL FORMATION. 191 from the bench, and joined with another of the same dimensions, butof larger or smaller net-work. These screens are remarkably dura-ble, and are not the least feature which has tended to bring coalBreakers into universal use. This process for crimping thick iron wire has introduced severalnew and important objects of manufacture, such as iron wire portablebedsteads, fences and ornamental railings, chairs, sofas, & FIG. 55.—IHOX RAILING. Walker & Son, at the corner of Sixth and Market streets, Philadel-phia, have a very extensive establishment exclusively devoted to theproduction of these articles, which, at no distant day, will supersedemost of the same articles now made of wood. After the coal leaves the screen and falls into its appropriateshutes, railroad cars are hauled immediately along side the openings,which, being raised up like the wickets in a mill dam, the coal fallsout into the car, and when a sufficient quantity is obtained, the shuteis closed, and then the coal leaves forever the scenes of its past his-tory, and is borne oflf to its future destiny. The size of chain generally used for hoisting coal is three-fourthsand seven-eighths of an inch; formerly smaller chains were used,and, in fact, smaller engines and lighter machinery ; but long expe-rience
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Keywords: ., bookcentury1800, bookdecade, booksubjectminesandmineralresources
