Sir, – Stuart Mathieson presents an interesting and informative article on the work of the American scientist Eunice Foote ("Eunice Foote, John Tyndall and the greenhouse effect", Science, August 9th). He is almost certainly correct that Foote's work may have been overlooked due to her gender. However, I think it is somewhat revisionist to credit her with the first demonstration of the greenhouse effect. As Dr Mathieson points out, Foote's experiments were concerned with the heating effect of sunlight on atmospheric gases. By contrast, John Tyndall studied the absorption by atmospheric gases of heat radiated from the Earth. The latter phenomenon, now known as the greenhouse effect, forms the basis of much of today's climate science, but is quite different from that studied by Foote. That said, it is indeed intriguing that Foote was the first to suggest that an increase in the concentration of carbon dioxide could have a warming effect on the earth's climate. As sometimes happens in science, it seems that she made the right prediction for the wrong reason! – Yours, etc,
Dr CORMAC
O’RAIFEARTAIGH,
School of Science
and Computing,
Waterford Institute
of Technology.