The Americana; a universal reference library, comprising the arts and sciences, literature, history, biography, geography, commerce, etc., of the world . plode. To makethese mines inoperative until they have beenproperly planted — for all mines must be an-chored at certain depths, varying accordinglyas the mines differ — there is a circuit-breakerconsisting of a composition of sugar and pow-dered chalk (good non-conductors), which sep-arates the ends of the wires in the mercury composition is poured in and allowed tocrystallize long before the two small batteriesare put in place. In a
The Americana; a universal reference library, comprising the arts and sciences, literature, history, biography, geography, commerce, etc., of the world . plode. To makethese mines inoperative until they have beenproperly planted — for all mines must be an-chored at certain depths, varying accordinglyas the mines differ — there is a circuit-breakerconsisting of a composition of sugar and pow-dered chalk (good non-conductors), which sep-arates the ends of the wires in the mercury composition is poured in and allowed tocrystallize long before the two small batteriesare put in place. In a brief while after themines are placed in the water, this compositionmelts and the weapons are ready for The electro-chemical mine is similarin principle, differing only in the nature of thematerial of the circuit-closer. An acid is setfree by the tilting, which, by coming in contactwith the two elements of a battery attached tothe ends of the firing-circuit wires, creates acurrent strong enough to heat the platinum fila-ment of the primer. Naval Defense Mines.— There is a form ofelectro-contact mine now carried by the heavy. Fig. 9.—Plan of a Mine Field. Mines are distributedin groups and electrically controlled from shore. Ves-sels avoiding one group will certainly pass over field is swept by battery fire, and illuminated bysearchlights at night, to prevent counter-mining. of rendering an enemys mine fields ineffective,either by cutting his electric cable connectionsor by exploding the mines by the shock ofcounter-mines fired in their work involves a great deal of risk, is veryhazardous, and must be carried out under coverof night or fog and with the utmost delibera-tion. The chances of its success are reducedto a minimum in the face of the powerful elec-tric lights and the rapid-fire guns that shouldalways command the approaches to the minefields. See Torpedoes. Robert G. Skerrett,Formerly of the A^azy Department, Was
Size: 2102px × 1189px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, bookcentury1900, bookdecade1900, bookidamericanaunivers14newy
