oil safety lamps. George Stephenson came from a mining family and by 1804 had secured the post of brakesman at Killingworth colliery. He was present at both the 1806 and 1809 explosions in the pit. By 1810, he was engineman and responsible for machinery both above and below ground. The pit was a gassy pit and Stephenson took the lead in work to extinguish a fire in 1814. For some years prior to 1815 he had been experimenting on the blowers or fissures from which gas erupted. He reasoned that a lamp in a chimney 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 him to determine the correct size and fineness for a miner's lamp. Davy was awarded the Rumford Medal and £1,000 by the Royal Society in 1816 and a £2,000 prize by the country's colliery owners, who also awarded 100 guineas (£105) to Stephenson. However, the Newcastle committee also awarded Stephenson a £1,000 prize collected by subscription. Dr. Clanny was awarded a medal by the Royal Society of Arts in 1816. Both the Davy and Stephenson lamps were fragile. The gauze in the Davy lamp rusted in the damp air of a coal pit and became unsafe, while the glass in the Stephenson lamp was easily broken, and allowed the flame to ignite firedamp in the mine. Later Stephenson designs also incorporated a gauze screen as a protection against glass breakage. Developments, including the Gray, Mueseler and Marsaut lamps, tried to overcome these problems by using multiple gauze cylinders, but glass remained a problem until toughened glass became available. Were the flame to go out in a lamp, then there was a temptation for the collier to relight it. Some opened the lamps to light tobacco pipes underground. Both of these practices were strictly forbidden, as they defeated the purpose of the safety lamp. The miner