1887.] NEW YORK ACADEMY OF SCIENCES. 117 



the day-laborer finds many intervals of rest daring his work ; 

 each exertion is usually followed by a short interval of rest, suffi- 

 cient for the refreshment of the muscles, and he might thus con- 

 tinue his exertions almost indefinitely were it not that the pecu- 

 liar and essential kind of rest which is found in sleep demands 

 its share of his time. Moreover, in ordinary labor, all of the 

 muscles of the body are seldom in action at once, the diversity 

 of effort permitting certain muscles to rest temporarily while 

 others are engaged. 



The boat-race involves the action of all the muscles, those of 

 the legs, arms, and shoulders, as well as of the back; and hence 

 the demands on the heart and lungs are the greatest possible. 

 The work which a rower performs in each minute of a four-mile 

 race is easily calculated. The distance — 21,120 feet — is traversed 

 in about 21 minutes. The speed is therefore practically about 

 1,000 feet per minute. At this speed the resistance to the boat 

 in the water is about 75 pounds. This resistance has been de- 

 termined experimentally as well as theoretically in England, tlie 

 average result being 75 pounds. The work per minute for eight 

 men is therefore 75,000 foot-pounds, or 9,375 foot-pounds (4.2 

 foot-tons) for each man per minute. 



At the rate of 350 foot-tons in ten hours, the day laborer per- 

 .forms work at the rate of only y^ of a foot-ton per minute. 

 The rower in the boat race therefore performs work each minute 

 equivalent to the work of seven strong laborers, or at the rate of 

 nearly one-third of a theoretical horse-power each minute during 

 the race. 



The question now recurs: for how long should these extra- 

 ordinary efforts be sustained? Four miles in distance and twenty- 

 one minutes in time, mark extreme limits of endurance, accord- 

 ing to all experience in boat-racing. And if races are practically 

 •decided at the end of the third mile, or whether they are so de- 

 cided or not, the fourth mile is a test, not of skill and muscular 

 strength, but of the hearts and lungs of the crews. 



This is rather serious business. Is it quite rational to make 

 the ultimate endurance of these vital organs in a dozen young 

 men a matter of sport and amusement? The muscles of the 

 Jieart and lungs are among those whose action is quite voluntary. 



