A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . Next akin to the time signals above described, and which act automatically upon clocks,either to drive the clock train or to correct the clock errors, are mere time signals, whichare extensively distributed throughout the country by the ordinary telegraph wires, and arelooked for at the various telegraph stations, in order to compare the office dials with Green-wich mean time, and to make the necessary correction; they are also redistributed by handthe fiKviiont
A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . Next akin to the time signals above described, and which act automatically upon clocks,either to drive the clock train or to correct the clock errors, are mere time signals, whichare extensively distributed throughout the country by the ordinary telegraph wires, and arelooked for at the various telegraph stations, in order to compare the office dials with Green-wich mean time, and to make the necessary correction; they are also redistributed by handthe fiKviiont thoy appeal, through sub-districts branching from junction stations. Large ELEOTKICITY. 485 black balls, hoisted in conspicuous stations, are also dropped daily by electric currents invarious places, for the general information of the public, or of the captains of ships.—C. V. w. ELECTRICITY for Blasting in Mines and Quarries. Professor Hare was the first whoentertained this idea, but Mr. Martin Roberts devised the following process :—In order notto be called upon to malie afresh a new apparatus for each explosion, Mr. Rob
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Keywords: ., bookcentury1800, bookdecade1860, bookpublishernewyo, bookyear1864
