Here is a late 1800’s to very early 1900’s rotary spark gap electric shock generator. it is mounted and housed housed in its original solid wood box. The unit consists of a heavy magnet with a hand cranked electrical coil in the center. The unit produces an electrical shock to the two hand-held wands . When the crank is turned, the shock produced feels surprisingly strong but is harmless. The item is unmarked but may possibly have been made by Kendrick and Davis. Box size is 5 ½' X 4” X 4”.