#49 When I worked for BT the Davy lamp was part of our kit, it was used for detecting gas or foul air in underground jointing chambers, we also knew hem as miners lamps. I believe they were invented about 1830 ish and the miners also used caged canary's as a safety precaution, I was tempted to keep my one and have it professionally cleaned up and polished to use as an ornament, but I never did. cheers JC