An antique miner's safety lamp, closely resembling the classic Welsh lamps made by E. Thomas & Williams. Key features – Construction: A dark metal body, a glass window protected by bars to shield the flame, and a rounded top cover featuring ventilation holes and a hanging hook. It served as a light source in coal mines; beyond illumination, the lamp acted as the mine's most critical safety tool. Methane detection: If flammable gas was present in the air, the flame would turn blue and form a "halo" above the wick. Oxygen deficiency: If oxygen levels in the mine dropped dangerously low, the flame would simply fade or extinguish, signaling the miners to flee immediately.