Safety lamp could create a sufficient updraft that firedamp would not penetrate down the chimney. Further observations of the speed of flame fronts in fissures and passageways led him to design a lamp with fine tubes admitting the air. Sir Humphry Davy was asked to consider the problems of a safety lamp following the Felling explosion. Previous experimenters had used coal gas (chiefly carbon monoxide) incorrectly, believing it to be the same as firedamp. Davy however performed his experiments with samples of firedamp collected from pits. As an experimental chemist, he was familiar with flames not passing through gauze; his experiments enabled
Flash-lamp Flash-lamp The electric flash-lamp uses electric current to start flash powder burning, to provide a brief sudden burst of bright light. It was principally used for flash photography in the early 20th century but had other uses as well. Previously, photographers' flash powder, introduced in 1887 by Adolf Miethe and Johannes Gaedicke, had to be ignited manually, exposing the user to greater risk. The electric flash-lamp was invented by Joshua Cohen (a.k.a. Joshua Lionel Cohen of the Lionel toy train fame) in 1899, and by Paul Boyer in France. It was granted U.S. patent number 636,492. This flash of bright