A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . s an electrical current circulatesin the wire; and its ends be-come respectively north and southpoles. A narrow plate of iron,an armature, as it is termed, ismounted on pivots in front of theends or poles of the magnet; itcarries a vertical stem upon whichthe hammer is fixed. Every timethe iron bar is magnetic the arma-ture is attracted, and the hammerstrikes the bell. The spring orcontact-maker for introducing thecurrent of electricity into the cir-cuit, is sho
A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . s an electrical current circulatesin the wire; and its ends be-come respectively north and southpoles. A narrow plate of iron,an armature, as it is termed, ismounted on pivots in front of theends or poles of the magnet; itcarries a vertical stem upon whichthe hammer is fixed. Every timethe iron bar is magnetic the arma-ture is attracted, and the hammerstrikes the bell. The spring orcontact-maker for introducing thecurrent of electricity into the cir-cuit, is shown in front on theright-hand side. This is Mr. Walkers bell for signalling railway trains from station to sta-tion. The language consists of o:ie or more blows. One, two, and three blows, are thesignals for common purposes ; half a dozen blows is the limit. The acknowledgment of asignal is its repetition. By a simple arrangement of an , that moves in fellowshipwith the hammer, the eye, as well as the ear, may read the bell-signals. Fig. 272 shows another application of the direct action of an electro-magnet in produc- 272. l^m^^
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Keywords: ., bookcentury1800, bookdecade1860, bookpublishernewyo, bookyear1864
