314 KEPORTS ON THE STATE OF SCIENCE. — 1915. 



According to Professor Huntingdon (see Section I.b), temperature 

 is particularly debilitating at its extremes of heat and cold; we 

 should therefore expect the lowest output and most numerous 

 accidents in winter between 8 and 10 a.m. and, if at all, 5 and 7 p.m. 

 (earlier and later factories are not working full) ; in summer from about 

 12 A.M. to 3 P.M. ; the whole year round, then, minima of output and 

 maxima of accidents should occur round 9 a.m., 2 p.m., and 6 p.m. 

 But, when we look at the accidents at Eenolds' (Table XVTI.) we see 

 clearly how the seasonal variations are only a minor factor when com- 

 pared with fatigue from previous duration of work. In the total the 

 maxima of accidents are not at 9 a.m., 2 p.m., and 6 p.m., but from 

 11-12 a.m. and 3-4 p.m., after three hours' and one hour's work 

 respectively. Temperature, however, certainly appears as a modifier 

 of the influence of fatigue from previous work ; in winter the cold hours 

 8-10 a.m. have a much higher proportion of the day's accidents distri- 

 buted to them than they have in the total ; and similarly in summer 

 the hour 3-4, though here it would not have been heat so much as 

 the after-effects of heat, that would be potent. 



From the figures it is impossible to infer, of course, whether 

 extremes of temperature modify the accident distribution by directly 

 producing dangerous circumstances such as fingers numb from cold, or 

 whether extreme temperature acts rather as an indirect influence on 

 accidents by enabling a duration of work to result more surely in fatigue 

 (see Section I.). 



2. The second main condition whose results can be sought by com- 

 paring different curves is that of the nature of the worker, and mainly 

 his age and sex. 



In the accident distribution of the Illinois manufactures 

 (Table XTII.) it has been possible to distinguish women's accidents and 

 also accidents to girls and boys under eighteen ; in the accident distri- 

 bution of the English cotton industry (Table IX. a and Diagram III.b) 

 women's accidents are also separately classed and similarly the 

 accidents of boys of eighteen or under in the comparison of earlier 

 and later ' work-hours ' (Table IX. b) in iron and steel and engineering. 



One divergence which women's and boys' curves show from the 

 normal occurs in the women's high accident rate in the morning as 

 compared with the afternoon spell. In the English cotton industry 

 (Table IX. a), the average of the hourly accidents in the morning spell 

 and in the afternoon spell is for men respectively 261'8 and 239'6; 

 for women 155"4 and 99'6; in the Illinois manufactures similarly, the 

 hourly average morning and afternoon is for all workers 1,212'6 and 

 1,212-0, for women 28-80 and 24-23. 



The main divergence within the spell from the normal which 

 women's and boys' accident curves show is the almost complete 

 absence of the normal decrease in accident in the last hour of the 

 spell. In the cotton trade, there is a continual increase of women's 

 accidents throughout all spells and similarly in the Illinois morning 

 spell for women and boys, and there the boys' accidents between 

 6 and 5.59 are particularly high considering how many leave work 

 at five. 



