No fitting of a boiler is more important than the water-gauge, which shows the level at which the water stands.
It has a horizontal boiler six inches long, safety-valve, and water-gauge.
A water-gauge in plain sight keeps the driver informed at all times as to the amount of water in the boiler.
“We are going to have a bad night of it,” observed John Marrot as his mate examined the water-gauge.
A third wave was noticed within an hour, raising the water-gauge over a foot.
Will Garvie consulted the water-gauge for a moment and then opened the iron door of the furnace in order to throw in more coal.