Michael Salt Water? Edesess, in Technology Review (Nov.-Dec. 1982), Room 10-140, Massachusetts Insti- tute of Technology, Cambridge, Mass. 02139.
In 1902, the Russian scientist A. von Kaleczinsky was surprised to find subsurface temperatures of over 185OF in Lake Medve, Transylvania (now part of Rumania). Today, researchers are capitalizing on his dis- covery to provide low-cost energy and heat in remote areas.
Salt water is the key to Lake Medve's warmth: Such "solar ponds" contain...