This is ace - a carbide lamp made from a few PVC pipe fittings, epoxy, etc. There is something nice about  carbide light that's more comforting than the starkness of LEDs.

https://www.youtube.com/watch?v=fM1Np8O-D_w

It is not the only carbide lamp made from drain fittings, although brass was considered a more reliable material. Here is a picture of the generator for one such lamp, raffled at the Aber Caving Club 50th anniversary a couple of years ago. It was manufactured by Mike Harris, at one time fairly well known in the Mendips.