National Geographic : 1969 Jan
Parting the shadow s All but invisible in a screen of maples and flowering goldenrod, two men stand in the shadows 75 feet away. But an infrared thermograph strips off their covering. In 30 seconds the instrument takes 10,000 heat measurements from the brush and converts them into a color picture that eerily exposes sunken nuclear submarine Thresher and the lost hydrogen bomb off Palomares, Spain. Two recent underwater archeological ex peditions supported by the National Geo graphic Society, through its Committee for Research and Exploration, have employed sonar techniques. One, organized by Dr. George F. Bass, As sociate Professor of Classical Archeology at the University of Pennsylvania, sought to locate presumably Roman or Greek ship wrecks which had yielded bronze statues to sponge-draggers' nets off the Turkish coast.* Two sunken ships were spotted for future exploration by divers. The other, led by Dr. Philip K. Lundeberg and Alan B. Albright of the Smithsonian In stitution, searched in Lake Champlain off Schuyler Island, New York, for remains of Benedict Arnold's fleet. A penetration sonar device developed by Dr. Harold E. Edgerton at the Massachusetts Institute of Technology was towed behind the search boat. Its sound waves located two submerged objects which, when divers reach them, may prove to be two Revolutionary War gondolas, the Providence 72 and the New York, that helped frustrate the British advance in 1776. Can sensing instruments that work such wonders on the ground or in aircraft do even better in orbit about the earth? Not all scientists or Government officials agree, and some are critical of the rosier as pects of plans announced in the past two or three years for earth resources satellites. Moreover such plans have been forcibly de layed by sharp cuts in the Federal budget for space programs. Yet the evidence is strong that at least some of the sensing techniques offer tremendous advantages at altitudes where one can see the forest instead of the trees. And the truth may be reflected in the comment of a Lockheed engineer, Louis A. Riedinger, that "we over estimate the near future and underestimate the far future." If that indeed be true, orbital sensing has a definite, and expanding, future. There is little debate about weather obser vations from space. They can save builders, farmers, and property owners 21/2 billion *See "New Tools for Undersea Archeology," by George F. Bass, NATIONAL GEOGRAPHIC, September 1968.