of the tubes, the air would get in better, and the effect in preventing
explosion would be the same.

He was encouraged to persevere in the completion of his safety-lamp by
the occurrence of several fatal accidents about this time in the
Killingworth pit. On the 9th November a boy was killed by a blast in the
_A_ pit, at the very place where Stephenson had made the experiments with
his first lamp; and, when told of the accident, he observed that if the
boy had been provided with his lamp, his life would have been saved. On
the 20th November he went over to Newcastle to order his third lamp from
a plumber in that town. The plumber referred him to his clerk, whom
Stephenson invited to join him at a neighbouring public-house, where they
might quietly talk over the matter, and finally settle the plan of the
new lamp. They adjourned to the "Newcastle Arms," near the present High
Level Bridge, where they had some ale, and a design of the lamp was drawn
in pencil upon a half-sheet of foolscap, with a rough specification
subjoined. The sketch, when shown to us by Robert Stephenson some years
since, still bore the marks of the ale. It was a very rude design, but
sufficient to work from. It was immediately placed in the hands of the
workmen, finished in the course of a few days, and experimentally tested
in the Killingworth pit like the previous lamps, on the 30th November.
At that time neither Stephenson nor Wood had heard of Sir Humphry Davy's
experiments nor of the lamp which that gentleman proposed to construct.

An angry controversy afterwards took place as to the respective merits of
George Stephenson and Sir Humphry Davy in respect of the invention of the
safety-lamp. A committee was formed on both sides, and the facts were
stated in various ways. It is perfectly clear, however, that Stephenson
had ascertained _the fact_ that flame will not pass through tubes of a
certain diameter--the principle on which the safety-lamp is
constructed--before Sir Humphry Davy had formed any definite idea on the
subject, or invented the model lamp afterwards exhibited by him before
the Royal Society. Stephenson had actually constructed a lamp on such a
principle, and proved its safety, before Sir Humphry had communicated his
views on the subject to any person; and by the time that the first public
intimation had been given of his discovery, Stephenson's second lamp had
been constructed and tested in like manner in the Killingworth