This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1889 edition. Excerpt: ...run at from 100 to 120 feet per minute. The best speed for large pumping engines is obtained by multiplying the square root of the length of stroke of the piston by 80. Ratio Of The Aeea Of Subsidiary Cylinder And Area Of Slide Valve. For Single Cylinder Engines. Bule.--Divide the area of slide valve by 3 and the quotient equals area of subsidiary cylinder. Example.--A slide valve 4J inches long by 8 inches wide. 4 5 x 8 = 36 inches area of valve.--=12 inches area of subsidiary or valve-moving cylinder, o or, say, 4 inches diameter. Foe Compound Engines. Mule.--Divide the areas of the two slide valves, added together, by 5; the quotient equals the area of the subsidiary piston. Example.--High pressure slide valve 4 inches long by 8 inches wide; low pressure slide valve 4-inches long by 11 inches wide. 4-5x8 = 36 inches. 4-5 x 11 =49-5 inches. 36-)-49 5 = 85 5 inches area of the two slide valves. 85 5----= 17 1 inches area of subsidiary cylinder, say o 5 inches diameter. The Cataract Governors are usually made the same diameter as the subsidiary cylinder. Feed Pumps. 15 gallons of feed water is usually allowed for each nominal horse-power per hour. 2 to 2-gallons per hour for each indicated horse-power. The ratio of area of steam cylinder to area of pump barrel varies from 2 to 2 to 1. Surface Condensers. 2 square feet of cooling surface should be allowed for each indicated horse-power; and 6 6 square feet for each nominal horse-power. 1 12 gallons of circulating water should be provided for each square foot of cooling or tube surface, or from 4 to 5 gallons of circulating water for each pound of steam to be condensed. Circulating tubes are made from. . inch to 1 inch outside diameter. Superficial area of external surface of tubes per...