Mystery Object #4 ANSWER

Like what I make? Want fewer sponsorship ad reads? Consider contributing to my Patreon at patreon.com/OurOwnDevices

In my last video, I showed you an unusual miners' safety lamp with a blue rather than transparent glass screen and asked you to guess what it was used for. Such lamps were used by British Air Raid Protection (ARP) organizations during the Second World War (primarily during the 'Blitz' of 1940-1941) to mark the positions of ruptured gas mains without igniting them, the blue colour preventing German pilots from spotting and targeting the lamps from high altitudes.

*Note: I did manage to find one of these on eBay, but for some reason it was flagged and confiscated by eBay's Global Shipping Service, who issued refunds to both me and the seller and kept the lamp...

SOURCES:
museumcrush.org/a-visual-history-of-the-miners-saf…
www.ww2civildefence.co.uk/blog/arp-hailwood-ackroy…