38 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



Fig. 460. 



Apparatus for Detonating Gases by the Magneto- Electric 

 Spark. (Fig. 460, as above.) Round the soft iron lifter 

 of a horse-shoe magnet capable of carrying fifteen or twenty 

 pounds, ten or twelve feet of insulated copper wire are 

 wound. To the ends of the coil two thick copper wires are 

 to be soldered in order to form a complete metallic circuit 

 when the lifter is in contact with the poles of the magnet. 

 The magnet is mounted, poles upwards, on a wood stand, 

 having a pillar Avith an arm or lever passing through a 

 mortice in the top of it, for the purpose of removing, by a 

 sudden jerk, the lifter from the poles of the magnet. In 

 front of the magnet a glass tube is fixed, having its top 

 closed by a cap of box-wood, through which the copper 

 wires soldered to the extremities of the coil pass, as near air 

 tight as possible, into the glass tube ; the end of one wire 

 being flattened, is bent at right angles and well amalgam- 

 ated. The other, which is straight, can be brought down 

 or removed from it by means of the lever. The whole 

 arrangement will be readily understood by a simple inspec- 

 tion of the figure. The mixed gases are introduced into the 

 tube, G, by means of a bent or flexible tube. On giving 

 the lever, E, a smart blow with the palm of the hand, the 

 iron lifter, A, B, is suddenly removed from the poles of the 

 magnet, a current of electricity is induced in the coil, con- 



