American Scientist

Vol. 42, No. 2 (APRIL 1954)

FRESH WATER FROM THE OCEAN, by Cecil B. Ellis et al; xi + 217 pages; 41 figs.; $5.00; Ronald Press, 1954.

This Conservation Foundation study by members of the staff of Nuclear Development Associates is a highly readable account of the remarkable progress made in recent years toward utilizing sea water as a source from which to meet the expanding needs of mankind for fresh water. The prospects for salt-water conversion in quantities sufficient to meet the needs of a modern city or of a large irrigation project, at costs that are not prohibitive, are competently analyzed. Each proposed conversion method is described, explained, and evaluated. For the first time, all aspects of this potentially epoch-making development in science and technology are brought together in a single volume.

“Of the many processes now known for purifying sea water, the electric membrane method is expected to be the cheapest.” This method has been developed only within the last few years and it is not possible to determine with precision the costs for a large plant that might be built with the new membrane materials at some future date. Nevertheless, the prediction seems justified that further research and pilot-plant tests will make possible, in the near future, the extraction of fresh water from the ocean on a scale of a thousand million gallons per day at a total cost of about 30 cents per thousand gallons at cheap-power locations. This price level may be within the reach of many large cities and industries, but it is far above that at which irrigation can be economically practiced.

The next cheapest method, especially for plants producing a million gallons per day or less, is compressive distillation. Competing processes are the multiple-effect distillation method, the supercritical distillation method and the freezing method. None of these “seems likely to better the 70-cents-per-thousand-gallons level by any means foreseeable at this time.”

Perhaps the most hopeful note sounded by this investigation pertains to the use of slightly brackish water, sources of which are numerous throughout the world, rather than sea water. The electric membrane method should be quite economical for this conversion in most locations. Small-scale industrial, irrigation, and stockfarm use of brackish water seems to be within the range of practical development.

Kirtley F. Mather (1888–1978), the first editor of American Scientist 's Scientists' Bookshelf, was a geologist and professor at Harvard University. He served as president of AAAS in the 1950s, during which time he also spoke out against the McCarthy-era inquisitions. This was not the first time Mather had advocated for freedom of expression: In the 1930s, he refused to take a "teachers' oath" proposed by the Massachusetts state legislature. In a 1996 biographical sketch of Mather for GSA Today, Kennard B. Bork notes, "Mather was happy to pledge allegiance to the federal government when he was inducted into the U.S. Army, but he rebelled against state fealty oaths for faculty members at private universities." Among Mather's books are The Earth Beneath Us (1964) and, with coauthor Dorothy Hewitt, Adult Education: A Dynamic for Democracy (1937). Bork's 1994 biography of Mather is titled Cracking Rocks and Defending Democracy.