Explosion of mines at a distance
Journal of the Franklin Institute
Explosion of ,Mines at a distance. M. Dmnoncel has conceived the idea, which we think chap , py one, of substituting the mechanical action of electric currents, in place of their physical action: and he has made an apparatus of very little cost, work. in~ at all distances, and capable of acting on an unlimited number of mines at a time. Let us suppose an electro-magnet of fine wire, fixed in one of the walls of a little oaken box; tile spring armature carrying a detent button: a vertical
... : a vertical match-holder is secured to a spring strongly bent by this button; along the path which the match will describe when the spring unbends, is sprinkled tine powder communicating with a fuse which transmits the ignition to the mine. Every thing being thus arranged, the current is established; the elee. tro-magnet attracts its armature; the spring escapes; the match rubs and is ignited, and the mine explodes. If it is required to explode a certain number of mines at a distance from each other, the current passes from one apparatus to the other. To effect this, M. Dumoncel adds to the ap. paratus above described, a plate, against which the spring which carries the match rests when unbent, anti this is made to close a second circuit, and so on.--Cosmos, iv, p. 29. Why not simply connect all the electro-magnets in one circuit ?--ED.