In 1854 Bowditch brought out a regenerative lamp and, owing to the excessive publicity which this lamp obtained, he is generally credited with the inception of the regenerative burner. This principle was adopted in several lamps which came into use later. They were all based upon the principle of heating both the gas and the air required for combustion prior to their reaching the burner. The burner is something like an inverted Argand arranged to produce a circular flame projecting downward with a central cusp. The air- and gas-passages are directly above the flame and are heated by it. In 1879 Friedrich Siemens brought out a lamp of this type which was adapted from a device originally designed for heating purposes, owing to the superior light which was produced. This was the best gas-lamp up to that time. Later, Wenham, Cromartie, and others patented lamps operating on this same principle.
Murdock early modified the Argand burner to meet the requirements of burning gas and by using the chimney obtained better combustion and a steadier flame than from the open burners. He and others recognized that the temperature of the flame had a considerable effect upon the amount of light emitted and non-conducting material such as steatite was substituted for the metal, which cooled the flame by conducting heat from it. These were the early steps which led finally to the regenerative burner.
The increasing efficiency of the various gas-burners is indicated by the following, which are approximately the candle-power based upon equal rates of consumption, namely, one cubic foot of gas per hour:
Candle-power
per
cubic foot of
gas
per hour
Fish-tail flames, depending upon size 0.6 to 2.5 Argand, depending upon improvements 2.9 to 3.5 Regenerative 7 to 10
It is seen that the possibilities of gas lighting were recognized in several countries, all of which contributed to its development. Some of the earlier accounts have been drawn chiefly from England, but