388 POPULAR SCIENCE MONTHLY 



Turning now to the Olympic records, we may notice that the 200- 

 and 400-meter stars lie close to the line; but slightly above the nearest 

 corresponding world's records. None of the Olympic record stars lie 

 below the corresponding world's records; but the 100- and 800-meter 

 stars lie close to the corresponding dots. The farthest away from the 

 line is the 42,190-meter star. It is to be. remembered, however, that 

 the Marathon race is run over country roads, up hill and down dale; 

 whereas all the other races are run on a smooth and level track. This 

 circumstance may account for all, and must at least account for part, of 

 the fact that the Marathon record is 10.7 per cent., or 1,128 seconds, be- 

 hind the time set by the straight line. As for the smaller discrepancies 

 in the other Olympic records, it is to be remembered that the contest- 

 ants in Olympic games are amateurs, whereas the world's records are 

 the best that professional as well as amateur champions have been able 

 to secure in all racing annals up to date. 



So far as appears on its face, the illustration suggests that the ex- 

 isting world's records offer a better chance of being lowered between 

 500 and 5,000 meters, than those below 500 meters, or those between 

 5,000 and 12,000 meters. It is, in fact, generally conceded that races 

 up to the quarter mile (400 meters), inclusive, are the most stren- 

 uous, and that races of from half a mile to three miles usually 

 leave the runners in a less completely exhausted condition. If this con- 

 cession be denied, and we tahe it for granted that all these records from 

 100 meters to 50,000 meters call for like strenuousness of sustained 

 effort and degree of physical exhaustion from equally good athletes, it 

 is hard to explain the oscillations of the record dots in groups from one 

 side of the straight line to the other. 



The straight line in the illustration stands, however, for much more 

 than a mere indication of possibilities in regard to records. It also 

 involves the conclusion that any record-making runner becomes ex- 

 hausted very rapidly as his average speed is increased. For example, 

 in the above table of Olympic records, it appears that the athlete Shep- 

 pard held an average speed of 7.09 meters-per-second over the 800- 

 meter course; but only C.16 meters-per-second over the 1,500-meter 

 course. We may safely assume that Sheppard arrived in each case at 

 the winning post, " run out " or practically exhausted in running 

 power; because if he had arrived with any residual running energy, he 

 would have thrown it into acceleration on the last lap. Consequently, 

 when he ran at 6.16 meters-per-second he ran himself out in 243.4 

 seconds; but when he increased his average speed, to 7.09 meters-per- 

 second, he ran himself out in 112.8 seconds, or in less than half the 

 time. That is, increasing his average speed 15 per cent, exhausted him 

 in-46.3 per cent, of the time. The law of the straight line in the illus- 

 tration is, in fact, that the time of exhaustion is inversely as the ninth 



