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
Signal lamp lamps are still used today, as a backup device in case of a complete failure of an aircraft's radio. Light signals can be green, red, or white, and steady or flashing. Messages are limited to a handful of basic instructions (e.g., "land", "stop", etc.); they are not intended to be used for transmitting messages in Morse code. Aircraft can acknowledge signals by rocking their wings or flashing their landing lights. Signal lamp A signal lamp (sometimes called an Aldis lamp, after Arthur Cyril Webb Aldis who invented a widely used design, or a Morse lamp) is a visual signaling device