The life of George Stephenson, railway engineer - Lighthouse ...

128 LIFE OF GEOEGE STEPHENSON. [chap. xi.
Whilst Sir Humphry Davy spoke thus bitterly in his private
letters, it is somewhat remarkable that he never once in his
published papers on the subject alluded to the fact that Mr. Ste-
phenson had constructed and tested a safety lamp in the mine,
months before his own was invented, although, as appears from
a private letter since published by Dr. Paris, in his " Life of
Davy," he was aware of the fact.* Nor did he refer to Hum-
boldt's contrivance of a safety lamp in 1796, on a plan similar
to that afterwards adopted by Dr. Clanny.f Indeed, the manner
in which he alluded to the last-named gentleman, who was the
first to show Sir H. Davy a safety lamp, imperfect though it
might be, was considered very disrespectful by Dr. Clanny and
his friends.
Now, that all angry feelings between the contending parties
have softened down, it is not perhaps very difficult to get at the
truth of this controversy. From what we have stated, we think
it must be admitted that the fact that carburetted hydrogen will
not explode down narrow tubes was discovered by Stephenson,
and that this fact or principle was applied by him in the inven-
tion of three successive lamps constructed under his directions,
all perfectly safe. Sir Humphry Davy discovered the same fact
about the same time, but most probably at a subsequent date, and
afterwards constructed a safety lamp which was preferred to that
of Stephenson, on account of its greater cheapness and light-
ness. Sir H. Davy himself acknowledges that the merit of his
lamp rested entirely on the discovery of the principle referred
to, which had previously been ascertained and verified by the
repeated experiments of Mr. Stephenson.
However great the merits of Mr. Stephenson in connection
with the invention of the tube safety lamp, they cannot be re-
garded as detracting from the distinguished reputation of Sir
Humphry Davy. His inquiries into the explosive properties of
carburetted hydrogen gas were thoroughly original ; and his dis-
covery of the fact that explosion will not pass through tubes of a
certain diameter, was doubtless made independently of all that
Stephenson had done in verification of the same fact. It even
* Paris's Life of Davy, 4to ed., p. 336.
t Journal des Mines, torn. viii. p. 839.