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SPIRIT OF DISCOVERY.

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IMPROVED SAFETY LAMP.

[Illustration]


Mr. Dillon has lately introduced to the notice of the scientific world, an
improvement upon the _Safety Lamp_ of Sir Humphry Davy, which appears to
us of sufficient interest for illustration in our columns. As the _Davy
Lamp_ is too well known to need special description here, it will be
merely necessary to allude to the principle of the invention, in order to
point out Mr. Dillon's improvement.

He maintains, in opposition to Sir Humphry Davy, that the Davy lamp acts
by its heat and rarefaction, and not from Sir H. Davy's theory, that flame
is cooled by a wire-gauze covering. He shows, by a simple experiment, that
the Davy lamp is not safe in a current of hydrogen or carburetted hydrogen
gas, and that many lives may have been lost from the confidence of miners
in its perfect safety. A current of hydrogen or carburetted hydrogen gas
steadily directed on the flame of the lamp from a bladder and stopcock,
_by cooling the wire gauze_, brings the flame of the lamp through the