This tank was made around 1930, by Bosch, but called American Bosch because after World War I, products with German names suffered a certain antipathy.
The tank was used over the kitchen sink and only for that. It had the usual interlocking controls to prevent accidental meltdown of the heater.
It vented into the room despite the fact that it generated 35,000 Btu, about the same as a 40-gallon tank heater today. There was no place for a flue.