What An "inch" Of Rain Means

Few people can form a deñnite idea of what is involved in the expression, "An inch of rain." It niay aid such to follo'w this cnrions calculation : An acre is equal to 6,272,640 square inches; an inch deep of water on this area wil] be as many cubic inches of water, which, at 227 to the gallon, is 22,000 gallons. This immense quantityof water will weigh 220,000 pounds, or 100 tons. One-hundredth at an inch (0.01) alone is equal to one ton of water to the acre.