THE QUESTION OP FATIGUE PROM THE ECONOMIC STANDPOINT. 293 



damp and warm conditions in a disinclination or actual inability to 

 perform active muscular work : ^ 



' Beginning as a mere inertness, accompanied by sleepiness, wliich 

 may readily be resisted for a time, it may pass into a genuine condition 

 of fatigue, and ultimately into the exhaustion of heat-stroke. Haldane 

 says of the Cornish miners of tin and copper : ' ' They do not .... 

 seem to be able to do more than a limited amount of work. The 

 leisureliness of all work in the mine is in very striking contrast to 

 what may be observed in any ordinary English colliery of about the 

 same depth." Pembrey, after studying the effects of warm moist 

 temperatures upon himself, medical students, and soldiers, concludes: 

 " The results show definitely that a man is much less efficient in a 

 warm moist atmosphere. ... A man can do far more work with less 

 fatigue at a low wet-bulb temperature than at a high one." 

 Pembrey and CoUis, in speaking of the physiological effects of the 

 warm moist atmosphere of cotton weaving, say: "The natural ten- 

 dency is for the nervous system to become less active, and for 

 muscular work to be diminished. In a weaving-shed, however, the 

 machine sets the pace, and the worker must neglect the dictates of his 

 sensations, which are the natural guardians of his health and well- 

 being. ... It is not surprising, therefore, that at the end of a day's 

 work, many of the weavers complain that they have no energy left, 

 have no great desire for food, and need only drink and rest." Boycott 

 says of mining in hot moist air : " My observations on miners . . . 

 lead me to conclude that their power of doing work under these cir- 

 cumstances is quite small." Mr. Cadman, Professor of Mining in 

 Birmingham University and late H.M. Inspector of Mines, gives more 

 detailed observations to the effect that from about 25° C. (77° F.) 

 wet-bulb reading, exertion begins to be accompanied by depression, and 

 disinclination to work increases rapidly with an increasing wet-bulb 

 temperature. At 27-80 C. (82° F.) " if clothes be removed and maxi- 

 mum body surface exposed, work can be done providing current of air is 

 available." At 29-4° 0. (85° P.) " only light work is possible " ; and 

 at 35° C. (95° F.) " work becomes impossible." Stapff observed in the 

 construction of the St. Gothard tunnel that the labourers, working in 

 an atmosphere often completely saturated with moisture, and with a 

 temperature rising at times beyond 30° C. (86° F.) as measured by the 

 dry-bulb thermometer, experienced not only great discomfort, but in- 

 difference, enervation, weariness, and exhaustion.' 



As regards different temperatures separately from humidity, a 

 chance of noting their result on working capacity is given by changes 

 of season and weather. In ' Harper's Monthly ' for January 1915, 

 under the heading ' Work and Weather,' Prof. Huntingdon traces 

 the variations in manual and mental work as the year proceeds. 



Combining various workers' piece-earnings for the same weeks in 

 the four years 1911-1914 in two Connecticut factories (one in 1911, the 

 other in 1912-1914), Prof. Huntingdon found that the ' lowest wages 

 are earned during January, then there is a rather steady increase 



* American Journal of Pvblic Health, vol. ii. p. 8C6 S. 



