214 THE COMPLETE WILDFOWLER 



instantly. The spark is of little use if it is after the type of 

 spark seen on ordinary sparking plugs for gas motors. It must 

 be such that it fuses off the ends of a bunch of three wires, 

 lying and insulated to the centre of the powder charge in the 

 ignition tube. These wires, seeing they are to be used, at 

 most, only a few times, may be made of copper or brass. 

 There is no need to go to the expense of platinum. The ends 

 of the sparking wires must be cased with thin paper, so that 

 a gap occurs to start the spark. The arc then takes place 

 between the wire ends and the wall of the tube, which is earth- 

 connected. If the powder lies close up to the sparking end of 

 the wire, it will then conduct the current without a spark, and, 

 instead of being an insulator, as we have said, the powder 

 becomes a conductor, though it may be a bad one. 



By arrangements as above, and by having the high-tension 

 circuit to the gun well insulated, good results can be obtained, 

 provided the coil is equal to its work, and the E.M.F. working 

 it is up to its voltage. We can, however, assure our readers 

 that an ordinary lock and striker mechanism in the breech of 

 a modern punt-gun is as handy as need be. But we suppose 

 we must be always trying something new. Unless a high- 

 tension switch is used in the electrical method of ignition, here 

 partly explained, the firing of the charge in the gun is slow, 

 appearing fully detectable in every case, just like a " hang fire." 

 Such a switch should be well designed to work with a spring 

 and placed near the breech of the gun, and, of course, perfectly 

 insulated. Undoubtedly the hang of the charge when the 

 induced current (through no switch) reaches the priming charge 

 direct from the coil, is due to the momentary resistance of the 

 powder as a medium through which the spark occurs. By this 

 it may be readily seen that the coil should be one capable of 

 sufficient power to overcome the resistance readily. 



Wadding for punt-guns cannot yet be beaten if it is of 

 oakum. In M.L. guns cut or punched card wads, if sent 



