A drop of rain is a very little thing, but here is a calculation of a
rainfall:
The rain fell in buckets, the thunder racketed terribly, and the
lightning drew zigzag lines of bright gold upon the violet sky.
“So you, too, don’t know what an inch of rain is exactly,”
said the weather clerk, as he looked at his rain-measuring
instrument. “Very few people do, it seems. I’ll explain it to
you.
“An acre is 6,272,640 square inches. An inch of water on an acre
is therefore 6,272,640 cubic inches. That amount, at 227 cubic
inches to the gallon, equals 22,000 gallons, or 220,000 pounds,
or 100 tons.
“An inch of rain is, in other words, rain falling at the rate of
100 tons to the acre.”
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