No More Learning

And Protagoras, in the second book of his "Comic His tories," relating the voyage of King           down the river, says something about the contrivances for procuring cold water, in these terms : " For during the day they expose it to the sun, and then at night they skim off the thickest part which rises to the surface, and expose the rest to the air, in large earthen ewers, on the highest parts of the house, and two slaves are kept sprinkling the vessels with water the whole night.