The fireman/water tender secures the fires because there is no visible water level in the gage glasses of a steaming boiler. Upon inspection, you observe condensate trickling down the inside of the gage glass. This indicates __________.
The fireman/water tender secures the fires because there is no visible water level in the gage glasses of a steaming boiler. Upon inspection, you observe condensate trickling down the inside of the gage glass. This indicates __________.