258 REPORTS ON THE STATE OE SCIENCE. — 1916. 



However, in the type-setting by hand, Bickerton represents the 

 average direction of curve in both spells, while Smith does so in the 

 morning spell and Howells and Fletcher in the afternoon. Five spells 

 cut of ten are therefore roughly typical. In the type-setting by 

 machine, Chester represents the average direction of curve in both 

 spells, while Newman does so in the morning and Marshall in the 

 afternoon. Four spells out of eight are therefore roughly typical. 



No -distinctive characteristic seems common to the two women 

 piece-hands, Eandall and Howells. 



Section III. 

 Faiigue as a Cause of Accidents. — Introduction. 



In the Interim Eeport published last year (1915), Section III., 

 page 17, an attempt was made to estimate how far the number of 

 accidents in each working hour could be expected to vary with fatigue. 

 It was there submitted that ' in the causation of many accidents the 

 psycho-physiological state of the victim was probably one of the 

 elements, though generally only as a condition enabling some mechanical 

 cause to take effect,' and further, that fatigue, the most important of 

 psycho-physiological states, would be evidenced by an increase of such 

 accidents towards the end of the working period. 



In testing the degree of fatigue by means of the accident curve, the 

 question, therefore, becomes important how far the mental or bodily 

 state of the injured men contributes to the occurrence of industrial 

 accidents. As an experiment a list was made from the particulars of 

 the causes of accidents presented by the Federation of Master Cotton 

 Spinners' Associations to the Departmental Committee on Accidents 

 1911 (Cd 5540), and in answer to the above question causes were 

 separated according to whether they indicated the state of body and 

 mind and hence fatigue to be contributable to the accident or not ; the 

 term ' contributable ' being applied to any factor that might possibly be 

 said to have contributed towards the accident. 



This list, which found only 75 out of 1,362 accidents to which 

 fatigue was not ' contributable,' has been so often quoted since the 

 publication of the Eeport (notably in the Brief prepared by Louis 

 Brandeis in defence of the Oregon Ten-hour Working Day) that a more 

 detailed study of the subject seems desirable. 



In particular it appears important that the possible contribution to 

 an accident of the injured man's state of mind and body be measured 

 more accurately ; in fact, that the possibility of such contribution be 

 ' graded ' according to whether it was very great, great, fair, and so on. 

 As will be seen below, in the classification of accidents at the munition 

 factory seven such grades are distinguished. 



The usefulness of such a measurement of the degree of contribution 

 to an accident by the victim himself lies mainly in the chance it offers of 

 a more accurate test of the influence of fatigue. In plotting the time- 

 distribution of accidents, only those types of accidents should now be 

 chosen that are attributable in great measure to the victim himself. If 

 fatigue is the main determinant, then in these classes the increase in 



