How ice was made before invention of electricity?
The Romans used to make ice in the deserts of North Africa or Palestine by taking advantage of the low humidity (and therefore the low temperatures at night). They would put what they wanted to freeze in a pit well-insulated with straw. The pit would be covered with highly-polished shields or other objects during the day, to reflect the heat of the sun; at night, the pit would be uncovered so that it could lose heat to the desert air. The same principle was used, for example, in British India. In times and places when the nights were cold, water would be poured into molds at dusk and allowed to freeze; then, at about 3 or 4 AM, the ice would be chipped out of the molds and rushed to an ice-house.
