Safety lamp, Davy, E. Simons self extinguishing device, marking: Simon's patent, Birmingham, c.1852

Safety devices were increasingly employed to prevent accidents arising from careless or improper use of safety lamps in mines, one of the most frequent temptations being for the miner to relight his own lamp in the working place. This is a self -extinguishing lamp of the Davy type, embodying improvements patented in 1852 by Mr. E. Simons. When screwing on the reservoir, a plate spring attached to the latter touches a lever on the inside of the cage, but allows it to retain a cup-ended lever in the vertical position. When unscrewing, however, the spring forces the lever aside, releasing the cup, which flies down on to the top of the wick.