96 pages. Printed by William Brendon & Son, Ltd., the Mayflower Press, Plymouth, England. There was a second edition in 1937. Lacks front free endpaper. Short closed tear in half-title. Rounded corners. All edges gilt. Original pale yellow endpapers. No inscriptions. 63 x 40 mm. Original black limp roan; covers with blind embossed borders; front cover gilt stamped 'With Compliments of The Superheater Company Ltd London'. WorldCat locates no copies worldwide of this 1927 impression of the first edition. This pocket manual was an essential daily tool for marine/ship, locomotive drivers, industrial, and railway engineers, tasked with generating power, keeping heavy industry moving, or operating transportation in the late 1920s when textile mills, steel factories, and early electricity generating plants were powered by giant stationary steam engines. Water expands roughly 1,600 times its size when it turns to steam. If a boiler got too hot, the pressure could spike and trigger a catastrophic explosion capable of leveling a factory building - a boiler explosion completely destroyed a four-storey wooden factory building in Brockton, Massachusetts, killing 58 people in the Grover Shoe Factory Disaster, 1905. By 1927, when this booklet was published, safety valves had transitioned from crude, dangerous experiments into highly sophisticated, precisely calibrated, and legally standardized mechanical instruments.