This section is from the book "The Tinman's Manual And Builder's And Mechanic's Handbook", by Isaac Ridler Butt. Also available from Amazon: The Tinman's Manual And Builder's And Mechanic's Handbook.
8X3 = 64X18 = 1152 ÷ 3 = 384 cubic inches, ÷ 231 = 1 gall. 2¾ quarts.
Rule. - Multiply the area of the base by the height, and one-third of the product will be the solid content.
Example.-Required the solid content in inches of a Cone or Pyramid, the diameter of the base being 8 inches, and perpendicular height 18 inches?