many years ago , about 60! a friend and i did a little caving near albany, ny. "back in the day' we used carbide lamps. we got thru a tight spot and the carbide lamp started acting up, my friend, a lot smaller than i, took the lamp and headed out, leaving me on the backside of the crawl space. being young and not to sharp, I decided to "see what i could see" using sulfur matches...
by the time he got back to me and took one whiff, we both decided to leave the cave for that day and now I see the fantastic photos taken with today's lights...Wow! thank you for the vicarious experience!
brian