Every-day Science: Volume 6. The Conquest of Nature
CHAPTER VII
GAS AND OIL ENGINES
(pp. 135, 136, 137). Gas engines. Quoted from the report of the Victoria and Albert Museum above cited.
(pp. 141-144). Gas engines and steam engines in the United States. Quoted from the report of the Special Agents of the _Twelfth Census_ of the United States, 1902.
(pp. 146, 147). The Svea heater. From an article by Mr. G. Emil Hesse in _The American Inventor_ for April 15, 1905.