However sincere Prince Philip's concern for the environment, these speeches, delivered between 1962 and 1977, seem like standard ""chicken-salad circuit"" fire. The Prince traces his own concern back to 1956 when he bought a camera at the Stockholm Equestrian Olympics. He began going out to snap birds and soon found himself becoming interested in the environment in general. ""Of all the remarkable shifts in popular interest since the war,"" says the Prince, ""nothing can quite compare with the sudden and explosive concern for the natural environment""--the environmental revolution. But as in all revolutions, the original leaders were ""dismissed as a lot of cranks,"" until evidence began pouring in to support their claims. Then, widespread ""rank and file"" enthusiasm led to ""the competitive rush to extremes""--a hindrance to any cause, although the Prince also warns against fragmentation of interests, and a return to apathy if people ""assume that things have changed for keeps."" He talks of controlling cur man-made as well as our natural environment, but perhaps his most interesting statement is from a speech to the Corporation of London inaugurating 1970 as European Conservation Year: ""We must face up to the absolute certainty,"" says Prince Philip, ""that we shall have to use de-salted sea-water in the very near future."" Otherwise, standard inspirational rhetoric.