Between the hottest hour of the day and the coldest hour of the night
there is frequently a change of four degrees in the Temperature of the
Sea. Taking one-fifth of the Atlantic Ocean for the scene of operation,
and the difference of four degrees to extend only ten feet below
the surface, the total and absolute change made in such a mass of
sea-water, by altering its temperature two degrees, is equivalent to a
change in its volume of 390,000,000 cubic feet.