Source : Webster's Revised Unabridged Dictionary (1913)

Drummond light \Drum"mond light`\ [From Thomas Drummond, a
   British naval officer.]
   A very intense light, produced by turning two streams of gas,
   one oxygen and the other hydrogen, or coal gas, in a state of
   ignition, upon a ball of lime; or a stream of oxygen gas
   through a flame of alcohol upon a ball or disk of lime; --
   called also {oxycalcium light}, or {lime light}.

   Note: The name is also applied sometimes to a heliostat,
         invented by Drummond, for rendering visible a distant
         point, as in geodetic surveying, by reflecting upon it
         a beam of light from the sun.