(under the class definition) Subject matter relating to combinations of a gas producing furnace and boiler when the structure of the boiler is intimately associated with the producer, so as to form a unitary structure, the gas from the producer being burned to heat the boiler.
SEE OR SEARCH THIS CLASS, SUBCLASS:
6+, for boilers heated by gas passing through a boiler from a gas producer, the heat of the hot gas being used for heating the boiler.
SEE OR SEARCH CLASS
48, Gas: Heating and Illuminating, for gas making plants including a boiler.
110, Furnaces, 229, for gas producer furnaces and see the notes therewith.
