Why? The Science of Athletics

278 WHY?-THE SCIENCE OF ATHLETICS position in which the shot rests on the hand just below the ear to the full extension of the athlete's arm ; a is the point at which the shot is given a final flick by the wrist and fingers and departs upon its path of flight acd. It is projected at an angle of 45 degrees and falls to the ground at d, but if the distance l represents, say, 45 ft. "then the kinetic energy exerted is 361 ft.-lbs. ; the velocity at the moment of departure is 38ft. per sec., and the time taken in accomplishing the distance l (45ft.) will be I·7 secs. The correct delivery angle of 45 degrees is along the line a·b, but, as we saw when discussing the long jump, it is the angle only at the instant of departure. Behaviour of Missiles in Flight The fact that many records have been refused on the grounds that the athlete was assisted by a following wind proves clearly how little was known to many judges con– cerning the exact science of the events of which they took charge at competitions. A strong following wind is undoubtedly of assistance to the short distance sprinter, who runs the whole of his course with a breeze behind him. It is far less certain that similar benefit is derived by the hurdler, high jumper and pole vaulter, while the effect ofa following wind upon certain missiles propelled through the air is definitely detrimental. Until quite recently, however, a following wind was considered to constitute a favourable circumstance, and officials, passing on records, were in the habit of assessing the strength of a prevailing wind by the deflection of a handkerchief, quite irrespective of such considerations as whether the handkerchief held up was of light silk and dry, or of heavy linen and damp. As a safeguard against this sort of unfair treatment of possible record-breakers, Mr. James Taylor, of Columbia University, U.S.A., has invented an automatic anemometer. No event, I think; presents such possibilities for. research where wind-effects are involved as does discus throwing, but it should be understood that from the moment the index finger of the thrower's hand imparts to the missile