The message
from "John" contains these words:

but usually for more interesting things like doing
high-current fun and game with the kids.

Could you elaborate please???

Turning pencils into short-lived incandescant lamps, melting salt with
carbon electrodes (one of these days I must make a rectifier so we can
electrolise some), running large electromagnets to do fun things with -
that sort of stuff.

--
Skipweasel
Pay no attention to that man behind the curtain.