When determining the contents of a boiler egg-ended as shown, it must be remembered that the boiler being circular in cross-section, the contents consist of a central cylindrical portion 26 ft. long, and two hemispherical ends that together make one sphere 6ft. in diameter. The area of cross-section of the cylindrical portion is found by squaring the diameter (that is, multiplying it by itself) and then multiplying by .7854. The contents will then be found if the area be multiplied by the length. Of course, all dimensions should be taken in like units, that is, in inches or in feet. Thus, in the example, the area of cross-section of the central portion will be 6 x 6 x .7854 = 22.27 sq. ft., and the contents will be 22.27 x 26 = 579 cub. ft. The contents of a sphere can be determined by cubing the diameter (that is, multiplying the diameter by the diameter and the product by the diameter) and multipljing by '5236. Thus the contents of a sphere 6 ft. in diameter will be 6 x 6 x 6 x .5236 = 113 cub. ft., so that the total contents of the boiler will be 579 + 113 = 692 cub. ft.

Since 1 cub. ft. of water contains 6.23 gal., the contents will equal 692 x 6*23 = 4,311 gal.

Determining Contents of Egg-ended Boiler.