Note 462 — Chapter XV
Reading edition
A practical engineer, with whom I had recently some conversation on this subject, informed me that when, many years ago, he was superintendent of one of the oldest Steam Navigation Companies, it was scarcely possible to maintain a pressure sufficient to keep the air out of the boilers, and the hissing noise it made, when rushing into the boiler through the reverse valve, was a not unfrequent tell-tale of the slackened efforts of the over-worked fireman.