Horse Power of Steam Boilers

—The usual value given to the term horse power as applied te boilers, is the evaporation of thirty pounds of water per hour, from feed water of 100° Fahrenheit, into steam at 70 Ibs. gauge pre ure, which in standard tests is considered to be equal to 34144 pounds of water evaporated from a feed water temperature of 212° F. into steam, at the same temperature. This standard ıs equal to 33305 B. T. U:per hour. Some engines can develop a horse power on this number of pounds of steam per hour, others on le , while many require more, hence it is about the present average capacity. Both engineers and steam users have accepted this standard.