t Committee, Sir
Humphry Davy, then in the full zenith of his reputation, was requested to
turn his attention to the subject. He accordingly visited the collieries
near Newcastle on the 24th of August, 1815; and on the 9th of November
following, he read before the Royal Society of London his celebrated
paper "On the Fire-Damp of Coal Mines, and on Methods of lighting the
Mine so as to prevent its explosion."

But a humbler though not less diligent and original thinker had been at
work before him, and had already practically solved the problem of the
Safety-Lamp. Stephenson was of course well aware of the anxiety which
prevailed in the colliery districts as to the invention of a lamp which
should give light enough for the miners to work by without exploding the
fire-damp. The painful incidents above described only served to quicken
his eagerness to master the difficulty.

For several years he had been engaged, in his own rude way, in making
experiments with the fire-damp in the Killingworth mine. The pitmen used
to expostulate with him on these occasions, believing his experiments to
be fraught with danger. One of the sinkers, observing him holding up
lighted candles to the windward of the "blower" or fissure from which the
inflammable gas escaped, entreated him to desist; but Stephenson's answer
was, that "he was busy with a plan by which he hoped to make his
experiments useful for preserving men's lives." On these occasions the
miners usually got out of the way before he lit the gas.

In 1815, although he was very much occupied with the business of the
collieries and the improvement of his locomotive engine, he was also
busily engaged in making experiments upon inflammable gas in the
Killingworth pit. According to the explanation afterwards given by him,
he imagined that if he could construct a lamp with a chimney so arranged
as to cause a strong current, it would not fire at the top of the
chimney; as the burnt air would ascend with such a velocity as to prevent
the inflammable air of the pit from descending towards the flame; and
such a lamp, he thought, might be taken into a dangerous atmosphere
without risk of exploding.

Such was Stephenson's theory when he proceeded to embody his idea of a
miner's safety-lamp in a practical form. In the month of August, 1815,
he requested his friend Nicholas Wood, the head viewer, to prepare a
drawing of a lamp according to the description which he gave him. After
se