Meanwhile, however, George was not entirely occupied with the consideration of his growing engine.  He had the clocks and watches to mend; he had Robert’s schooling to look after; and he had another practical matter even nearer home than the locomotive on which to exercise his inventive genius.  One day, in 1814, the main gallery of the colliery caught fire.  Stephenson at once descended into the burning pit, with a chosen band of volunteers, who displayed the usual heroic courage of colliers in going to the rescue of their comrades; and, at the risk of their lives, these brave men bricked up the burning portion, and so, by excluding the air, put out the dangerous fire.  Still, even so, several of the workmen had been suffocated, and one of the pitmen asked Geordie in dismay whether nothing could be done to prevent such terrible disasters in future.  “The price of coal-mining now,” he said, “is pitmen’s lives.”  Stephenson promised to think the matter over; and he did think it over with good effect.  The result of his thought was the apparatus still affectionately known to the pitmen as “the Geordie lamp.”  It is a lamp so constructed that the flame cannot pass out into the air outside, and so cause explosions in the dangerous fire-damp which is always liable to occur abundantly in the galleries of coal mines.  By this invention alone George Stephenson’s name and memory might have been kept green for ever; for his lamp has been the means of saving thousands of lives from a sudden, a terrible, and a pitiful death.  Most accidents that now occur in mines are due to the neglect of ordinary precautions, and to the perverse habit of carrying a naked lighted candle in the hand (contrary to regulations) instead of a carefully guarded safety lamp.  Yet so culpably reckless of their own and other men’s lives are a large number of people everywhere, that in spite of the most stringent and salutary rules, explosions from this cause (and, therefore, easily avoidable) take place constantly to the present day, though far less frequently than before the invention of the Geordie lamp.

Curiously enough, at the very time when George Stephenson was busy inventing his lamp at Killingworth, Sir Humphrey Davy was working at just the same matter in London; and the two lamps, though a little different in minor points of construction, are practically the same in general principle.  Now, Sir Humphrey was then the great fashionable natural philosopher of the day, the favourite of London society, and the popular lecturer of the Royal Institution.  His friends thought it a monstrous idea that his splendid life-saving apparatus should have been independently devised by “an engine-wright of Killingworth of the name of Stephenson—­a person not even possessing a knowledge of the elements of chemistry.”  This sounds very odd reading at the present day, when the engine-wright of the name of Stephenson has altered the whole face of the world, while Davy is chiefly