AS times get faster and faster, and record after record is lowered, one begins to wonder how far progress will ultimately go. But, however much the technique of athletics is improved, the athlete will always be up against the fundamental limitations imposed by nature on human effort. The exertion expended by a man running 100yds. in ten seconds may amount to as much as eight horse-power, and he may do enough work against the internal friction of his own muscles to lift him vertically as high as the cross of St. Paul's. In the final talk of his series, Professor Hill will discuss how science can investigate the onset of fatigue-an enquiry of the utmost importance in industry as well as in sport.
(Picture on page 662.)