SAFE FUN for HALLOWEEN
UPON arriving, every member of this Halloween party must be fingerprinted and “mugged” as regular routine for identification records in the archives. The newcomer presses the thumb of his right hand down on the “ink pad,” for which purpose ordinary carbon paper will do. This is pasted to a piece of sheet metal on a small box which contains two dry cells and a Ford vibrating coil, connected together as shown in Fig. 1. The “guard” presses a push-button switch the moment the guest touches the carbon paper and has his left hand on the table directly over another sheet-metal plate also wired up as indicated.