1919 Ward Water Tube Boilers Ad - "HIGHEST EFFICIENCY. 16.73 POUNDS WATER EVAPORATED PER POUND OF OIL."
1919 Ward Water Tube Boilers Ad - "HIGHEST EFFICIENCY. 16.73 POUNDS WATER EVAPORATED PER POUND OF OIL."

1919 Ward Water Tube Boilers Ad - "HIGHEST EFFICIENCY. 16.73 POUNDS WATER EVAPORATED PER POUND OF OIL."