THE MARTIN P. CATHERWOOD LIBRARY OF THE NEW YORK STATE SCHOOL OF INDUSTRIAL AND LABOR RELATIONS AT CORNELL UNIVERSITY Digitized by IVIicrosoft® $"" ^ f MINISTRY OF MUNITIONS. ^^ '^ HEALTH OF MUNITION WORKERS COMMITTEE. MEMORANDUM No. 21. AN INVESTIGATION OF .THE FACTORS CONCERNED '^IN THE CAUSATION OF INDUSTRIAL ACCIDENTS, x (By H. M. Vernon, M.D.) (pr^eentei ^o (parfiamenf 6p Command of %\ti pa/ee^. LONDON: PUBLISHED BY HIS MAJESTY'S STATIONERY OFFICE. To be .purchased through anv Bookseller or directly from H.M. STATIONERY OFFICE at the following addresse.s : [mpkrial House, Kingsway, Londojt, "W.C. 2, and 28, Abingdon Street, London, S.W, 1 ; 37, Peter Stkbbt, ManoeCEster; 1, St. Andrew's Crescent, Cardiff; 23, Forth Street, Edinburgh; or from E. PONSONBY, Ltd., 116, Grafton Street, Dublin. _; 1918. [Od. 9046.] D,.g,.^~§ §i^Wir^S^m HEALTH OF MUNITION WORKERS COMMITTEE. The Committee were appointed by the Minister of Mumtions, with the concurrence of the Home Secretary, " To consider and advise on questions of industrial fatigue, Hours of labour, and other matters afiecting the personal health and physical efficiency ot worKers in munitions factories and workshops." The members of the Committee are : — Sir George Newman, K.C.B., M.D. (Chairman). Sir Thomas Barlow, Bart., K.C.V.O., M.D., F.R.S. Gr. Bellhouse, C.B.E., Factory Department, Home Office. Professor A. E. Boycott, M.D., F.E.S. J. R. Clynes, M.P. B. L. CoLLis, M.B., Factory Department, Home Office. Sir Walter M. Fletcher, K.B.E., M.D., F.R.S., Secretary of Medical Research Committee. Leonard E. Hill, M.B., F.R.S. Samuel Osborn, J.P., Sheffield. Miss R. E. Squire, O.B.E., Factory Department, Home Office. Mrs. H. J. Tennant, C.H. E. H. Pelham (Secretary). The following Memoranda have now been prepared by the Committee : — No. 1. — Sunday Labour. No. 2. — ^Welfare Supervision. No. 3. — Industrial Canteens. No. 4. — Employment of Women. No. 5. — Hours of Work. No. 6. — Canteen Construction and Equipment. (Appendix to No. 3.) No. 7. — Industrial Fatigue and its Causes. No. 8. — Special Industrial Diseases. No. 9. — ^Ventilation and Lighting of Munition Factories and Workshops. No. 10. — Sickness and Injury. No. 11. — Investigation of Workers' Food and Suggestions as to Dietary. (Second Appendix to No. 3.) No. 12. — Statistical Information concerning Output in relation to Hours of Work. No. 13. — ^Juvenile Employment. No. 14. — Washing Facilities and Baths. No. 15. — The EfEect of Industrial Conditions upon Eyesight. No. 16. — ^Medical Certificates for Munition Workers. No. 17. — Health and Welfare of Munition Workers outside the Factory. No. 18. — ^Further Statistical Information concerning Output in relation to Hours of Work, with special reference to the Influence of Sunday Labour. No. 19. — Investigation of Workers' Food and Suggestions as to Dietary. (Second Appendix to No. 3. Revised edition.) No. 20. — ^Weekly Hours of Employment (Supplementary to Memorandum No. 5). No. 21. — An Investigation of the Factors concerned in the Causation of Industrial Accidents. Interim Repoet.^ — Industrial Efficiency and Fatigue. [Cd. 8511'.] (b 12099) Wt. 20716—6271 7500 5/18 H & S Digitized by IVIicrosoft® Memorandum No. 21. Health of Munition Workers Committee. AN INVESTIGATION OF THE FACTORS CONCEENED IN THE CAUSATION OF INDUSTRIAL ACCIDENTS. To the Rt. Hon. Winston Churchill, M.P., Minister of Munitions. • Sir, Tlie Committee beg to submit for consideration a Report by Dr. Vernon on certain inquiries made by lum into the causation of Industrial Accidents. In tlie course of Ms investigations he analysed about 50,000 accidents. The resulting information is, in the opimon ot the Committee, highly important and suggestive, and merits close consideration, ihe Report is the more valuable in that so far as the Committee are aware no similar mqmry has hitherto been undertaken, at any rate in this country. Signed on behalf of the Committee, GEORGE NEWMAN, M.D., Chairman. E. H. Pelham, Secretary. February, 1918. AN INVESTIGATION OF THE FACTORS CONCERNED IN THE CAUSATION OF INDUSTRIAL ACCIDENTS. By H. M. Veenon, M.D., Fellow op Magdalen College, Oxfoed, and Univeesity Lectuebe in Chemical Physiology, Assisted by W. Neilson Jones, M.A., Lectuebe in Botany at Bedford College, London.* Contents. Introduction Sources of tte Accident Data The Factors concerned in Accident Production I. — ^Accidents in relation to Speed of Production — (a) Hourly Variations of Accidents and of Output (6) Daily Variations of Accidents and of Output (c) Montkly Variations of Accidents and of Output II. — ^Accidents in relation to Fatigue III. — ^Accidents in relation to Psychical Influences and Alcohol Consumption IV. — -Accidents in relation to Nutrition V. — ^Accidents in relation to Natural and Artificial Lighting . ; VI. — Accidents in relation to Temperature A Comparison of Accident Frequency in different Factories, and in Men and Women The Prevention of Industrial Accidents Smnmarf Page 4 4 5 5 15 22 23 27 31 34 36 41 44 45 * In this investigation W.N.J, was responsible for the direct determinations of output in women turning fuse bodies and in men sizing fuse bodies, and for tabulating a seventh of the accident data, but owing to his taking up an appointment with the R,?r.A.S. as Lieutenant R.N.V.R., he had to relinquish the work and H.M.V. completed it alone. Property of .(8^12099) A 2 MARTIN P. CATHERWOOD LIBRARY Digitized by MicrcmUm SIME SCHOOL INDUSTRIAL AID LABOH mMlM Cornell University Introduction. Of recent years the causation of industrial accidents has b^^? ^f^^ff f l^^^Xi^S'Tc'ddS^^^ increases mining their hourly incidence,* and it has been found almost iii^^^i^^^y.*^"?^ ,^^^ or last hour but one of rapidly during the course of the day's work, and reaches i*^ maximum m the lastno incidence occurs the morning Ipell of work. It is frequently but not invariably found that ^J^^rs Jo conclude that fatigue in the afterLon speU, and these and other considerations have led most ^.f J^^Stlar^ough extremely is by far the most important factor concerned in acciden^ causation. ^''\^^l^''^'^'7orieUU with :the corre- numerous, aU without, exception sufier from one fatal de ect. TW>are m^noxase^corre^atea^ ^^^ spending output data. It is true that data showing hourly variations "* °^*PJ^^^T^fg^^e types of industry ently, but not on any considerable scale, and they do not for the most Pf J^^^*! *°X^ concerns as the accident data. Another serious defect present in aU the accident ^ata hith^o p^^ their method of tabulation. If the spell of work be from, e.g., 1 to 12, ^"^^ f^l^^^^ll TJ^^S^^^^^ no work- according as they occur from 7 to 8 (or 7 • 59), 8 to 9, and so on, oblivious of the fact ^Jf .P^^^J^Je down, man begins^his wU at the nominaLstarting time. ;He,usuaUy tates.ajout ^^^^'^^'^^^f^""^^^^^ M^t or the accidents occurring in the first hour relate to.abqut three-quarters of an hour of g^™T°2ably do workmen also slack off a few minutes before the end of the nominal stopping time and almost mvm^^^ so before the end of the afternoon spell. Hence the only safe plan is to cut off the ^^f^^^^'^^^fj^^^^ hours of each work spell, and consider as genuine only the number of accidents occurring m the mtermeaiate hours of fuU work. . j _ „ 1J„„ 4v, +1,0 fort, t.hat Another serious defect.to which mostaccident data are liable m greater or less degree hesm tie tact that the time of treatment of an accident does not necessarily correspond to the time of its °''<'^^'l°^^-^^f2 anv largely overcame this source of error by confining himself to accidents severe enough *« Fevent any work for the next 15 days or more, but such accidents occur so infrequently as to ^\J^Y iTr^^L^A collect in suffiqient. numbers ,for stati^tiQal purposes. In the present investigation, the defect mentionea has been overcome to some extent .by classifying different type? of accident sep^ra*©iy. ^^^ most suitable type of aoQideht is that in which foreign bodies,. such as .small particles of pietal ana.emCTy, lodge in the eye. A preUmi'nary attempt at removal by a friend is often made in_ the wor|8nop, but if this fails, the sufferer comes ahnost at once to the dressing .station to have it removed, ana it is very seldom that he comes again for a second treatment. Eye .accidents are not very numerous, and for most statistical purposes have to give way to,outs. These occur with, extreme frequency m-most enpneeriBg shops, and in that they bleed and become a nuisance, they generally compel the sufferer to come for treatment almost at once. Cuts generally need two or three re-diessings, so it is very important that the nurses should LQvariably recqrd whether .each case is a " first dressing " or not. Of other accidents, burns are generaUy treated soon after they occur, but by'no means always. Most unreliable of all are muscular strains and sprams, for it appears to, be the rule rather than the exception for a sufferer to postpone a visit to the dressing station for hours or even days. In order to obtain an idea as to the times at which the workers prefer to conae to the dressing station, septic cases and other previous injuries, when dressed for the first time, have been tabulated separately. No previous investigators appear to have allowed for any delay at all between the time of occurrence of an accident and the time of its treatment, though a few minutes must inevitably elapse. As the result of consultation with the nurses I have assumed that this time averages 5^ minutes, or that accidents occurring between, e.g., 7.30 and 8.30 would not bedressed and recorded by the nurse until 7.36 to 8.35. I am inclined to think that the time allowed is a minute or two too short, but the error is not large, and in any case it neces- sarily varies in different factories. Sources of the Acoeoent Data, AU of the accident and output data to be described were obtained at four munition factories. At factory A they were tabulated for 25J consecutive months, during the first three of which the total number of workers averaged ^feout .6,QQ0, ,and during the remainder of ithe time, over ;9,JQQ0. Half to two-,thiids of these workers were women, ,8^4 m(;{&t .pf tjiem. were making and loading ti^e fuses, biutabout an eighth of lihem were engaged on brass cartridge cases for small shells (chiefly 18 lb.). At the other three factories the data were tabulated for 9| to 13 months. At factory B, which was confined exclusively to the manufacture of 6-inch H.E. shells, there were about 2,100 workers. Two-thirds of them were men at the outset, but by the end of the statistical period they had dwindled to a third. At factory C, which was confined exclusively to the manufacture of 9-2-inch H.E. howitzer shells, there were about 1,700 workers, of whom four-fifths were men at the beginscumg of the jstatistical period, but wornen were gradually substituted and at the end formed nearly ^ half. At factory D, 9 • 2-inch and ] 5-inch shells were made, and of the 2,300 workers about three-fourths were men at the aatset, and rather more than halt, later on. The accident data at factory A were exceedingly well kept, as the Jime of dressing of fi^ach case was invariably noted, and special care was taken to designate correctly .all the first dressings. At- factories B and C th^ nurses were not so careful about noting the first dressings, ;and probacy aom«thing like a third of the cases recorded as first dressings were really second or subsequent dressings. Neveribheless, by allowing for this error these data have yielded valuable results. At factory D the times at which the ac^demts occurred were not always noted sufficiently carefuUy, but the first dressings were recoaded correctly. Factory A was erected shortly after the war began, but as it was fin exteasion from an old and well-estab- lished firm it got into thorough working order by July, 1915, and tjaere was very little change in the conditions of production from that time forward, except in respect of the hours of work. Factory C was erected con- siderably later, but by October, 1916, it had reached an output only 20 per .cent, less than the level it attained in Jaifijary, 1917, and which it kept from that time forward. Factory B worked up to its maximum by October 1916, and kept a level output until March, 1917, when a re-arrangement of the plant threw it back for two * For a nummary of i\^s,p investigations, see Report o£ Gfiimmittee oy\. " FfliigMB from the Econoraio Staad- poifi|;." flrit. Assn. Reports. 1915. p. 283 ; also " The Case for the Shorter Work Day." Matioaa.1 Con^ sumers League, New York, 1915, Vol. I, p. 360. f Bogardus, American Journalfof Sociology, November, 1911. Digitized by Microsoft® Marrh 1 qi 7 ^^f soon exceeded its previous maximum. Factory D did not rcacli a steady output Bntil ;ia^!^'i; ' ^° "^""^^^ later (^.e., for tke last three montks of the statistical period) its .plant was re- ?ntl W ff^'^'^Ti"^^ P^^""*- ^°'* °* *^^ ^^^^^'^^ ^* imtonea A, B and G were paid at individual .piece Ln+Lr -^ !^ at factory D were paid at a time rate, together with a bonus on the collective, outp-rt. of the lactory. lactones B, and D are all situated in the same district, within four miles of, each other, whilst factory A is in a different locahty. The total number of accidents and medical cases tabulated at *he various Factory A „ B „ C „ D Accidciiis. Medical Gases 23,M-2 3,361 10,627 10,560 370 5,^64 Total 50,093 3,731 The Factors concekned in Accident Production. Next to the factor of fatigue, speed of production is regarded by several investigators as the most important contHbutory cause of accidents, and I have come to the conclusion that speed of production is the essential factor m accident causation which can never be neglected. Its actiondepends especially on the degree of nervous and muscular co-ordination possessed by the worker, and on psychical conditions such as his alertness and attention. The various factors concerned in accident production may be classified under two main headings, aecrarding as they depend on the worker himself, i.e., are of personal origin, or depend on external conditions not directly under his control. Factors of personal origin — I- — Nervous and muscular co-ordination in relation to speed of production. II. — Fatigue. III. — Psychical influences. IV. — ^Nutrition and alcohol consumption. Factors of external origin — V. — Lighting. VI. — Temperature, humidity and ventilation. VII. — Defects of machinery, and absence of guards. Accidents in Relation to Speed of Production. Hourly Variations of Accidents and of Output. The accurate determination of the hourly variations in the output of a factory is much more difiicult than the i&vestigation of the accident incidence, and it was practically impossible to determine it every day over the period of months or years for which the accident data were collected. It will be seen, however, that output observations made at intervals of several months agreed very closely with one another, and so afforded an approximate index of the average output variations of the whole period. Fig. 1. — Output, of Fuze Bodies. /zo 110 ■,100 ^90 2-80 70 60 50 40 By excess , power load\ By enumeration tT=r3j- 10 II 11 I Z TIME. "V HOURS, Digitized by IVIicrosoft® Output variations were investigated in all four factories by the indirect method, first used by Abbe, of taking electric power consumption records, but such records were shown to be vaM by l^Xi.fT^rZ^l investigations made at factory A. The power suppUed to each of the numerous sections at this t^cto^ was registered by a separate watt-meter, and in one of these sections seven-eighths of the operatives were yo^King with lathes of identically the same pattern upon the same operation. This operation consisted i^ ™^g aluminium fuse bodies by means of capstan lathes, and there were about 170 women engaged on ir. xne energy required to drive the shafting and the lathes could be determined with moderate accuracy, lo^^ i«J^^^ the custom to leave all the lathes running continuously unless they were entirely out ot "se, and tney were not stopped when a fresh fuse body was clamped in or removed, or when the operative rested, iiie macmnery was started a few minutes before nominal starting time, and as the operatives were always slow m settling down to work there was an interval of about eight minutes during which the electnc power was employed solely in driving the shafting and the lathes. Then the power suppUed mounted up as the operatives graduauy got going, and reached its fuJl value when they were aU at work, about 20 minutes after nominal starting time. Hence the excess power load over and above that required to drive shafting and lathes was a measure ol tne output of the whole section, and in Fig. 1 is shown the average excess power load as determined during Hve days (M., T., W., Th. and F.) lying between April- 13 and June 7, 1916. The direct output of smaU groups of women was counted on each of six days spread over the same period, though not always on the same days as those for which the power records were taken. Altogether the output of 43 women was counted {i.e., tor one day each), and their average output is shown as a dotted line in Fig. 1. The average hourly output over the whole day was taken as 100, and a comparison of the two curves shows that the hourly variations corres- pond fairly well throughout the day. The only considerable difierence in the curves occurs between 11.30 and 12.0. The explanation of this difference depends on the fact that most of the workers were found to knock ofi work 3 to 5 minutes before the nominal stopping time, and so to lower their output during this half- hour period, whilst the individuals whose output was being counted worked on to the end, as they knew they were under observation. It follows, therefore, that power records afford a more reliable guide of output than- direct observations, as it is impossible to avoid completely the influence of the observer on the worker. They are like-wise very much easier to obtain. In factory A the power supplied to the different sections (as distinct from the lighting current) was regis- tered by 22 separate watt-meters, but as a rule only seven of these were read. In that nearly all of the accidents to be described were incurred by workers using lathes and drills, the meters registering the current to these sections of workers were chosen, and the excess power load curves given in the lower part of Fig. 2 represent the output variations of over two-thirds of all the lathe and drill workers in the factory. One set of observations was made in January, 1917, and another set in July, 1917. The meters were read on three consecutive days and three consecutive nights, and the relative hourly output variations shown by each of seven meter records calculated on an average value of 100. Then these 21 sets of relative values were averaged, and these grand average values are reproduced in Fig. 2, and quoted in Table I. A comparison of the winter and summer curves shows a close correspondence both for day and night shifts, whilst the day shift values correspond well with those obtained for the same sections during April to June, 1916, as can be seen from the Table. Hence it follows that the hourly variations of output remained nearly constant from April, 1916, till July, 1917. Table I. — Mean Output of Lathe Sections. Time. Day Shift. April to June, 1916. Jan., 1917. July, 1917. Night Shift. Time. Jan., 1917. July, 1917. 7.0 to 7.30 ... 7.30 to 8.30 8.30 to 9.30 9.30 to 10.30 10.30 to 11.30 11.30 to 12.0 1.0 to 1.30 1.30 to 2.30 2.30 to 3.30 3.30 to 4.30 4.30 to 5.30 5.30 to 6.0 50-8 99-4 110-3 111-1 f 112 -SJ 98-1 .1 108-4 69-9 107 104 106-3 f 108 -3J 60-7 '■51 t-2L 106-6 55-4 101-01 106-1 L107.3 111-6 r 110 -5 J 98-6 86-1 109-5 104 -4J 53-7 56-9 102 •5"! 104-7 t 109-3 f 111-oJ 102-2 106-9 6.30 to 7.0 7.0 to 8.0 8-0 to 9.0 9.0 to 10.0 10.0 to 10.30 11.30 to 11.45 11.45 to 12.45 12.45 to 1.45 1.45 to 2.45 2.45 to 3.0 3.30 to 3.45 3.45 to 4.30 4.30 to 5.15 5.15 to 6.0 6.0 to 6.30 56-6 99-9 "] 105-1 ^104-1 107 -3j 100-1 109-0 Digitized by IVIicrosoft® Time. Table II. — Output of Individual Sections. Men Tool- making. Men Controlling Automatic Machines. Men and Women Turning 2-lb. Shells. Women Turning Brass Time Fuses and Primers. Girls Drilling and and Finishing Fuse Rings. Women Turning Brass Fuse Rings and Fuse Bodies. Women Turning Aluminium Fuse Bodies. 7.0 to 7.30 7.30 to 8.30 8.30 to 9.30 9.30 to 10.30 10.30 to 11.30 ... 11.30 to 12.0 1.0 to 1.30 1.30 to 2.30 2.30 to 3.30 3.30 to 4.30 4.30 to 5.30 "5.30 to 6.0 Increase of output between 1st and 3rd or 4th hours of morning speU 107 •7J 103-5 90-2 111-5"] 103-8 1^ 104-0 f 103 -7J 50-2 105-7 3 per cent. 87-0 108-71 108-1 t 105-7 f 98 •8J 48-8 105-3 3 per cent. 52 105 105 110-1 f 113 -SJ 94-6 i-8^ i-4L 108-6 7 per cent. 59-6 100-5 104-9 110 111 107-2 :1 106-6 64-4 100-4 104-9 112-1 111-5 11 per cent. 107-2 97-8 12 per cent. 49-9 97-7^ 104-3 111- 111- 95-8 a 106-2 85-0 110- 105- 108-5 112-2^ 46-0 ::a 109-2 14 per cent 104-9 78 108 102 103-1 f 109 -7j 76-1 5-7^ J-4l 106-0 21 per cent. The hourly output variations in the individual sections corresponded fairly weU with one another, as can be gathered from Table II, which shows the averages of the January and July values for the day shift. In the morning speU the output was always, with two minor exceptions, at a minimum during the first full hour of work, and rose gradually to a maximum in the last or the penultimate hour. The actual amount of increase was very small (viz., 3 per cent.) in the two sections run entirely by men, was moderate in the mixed section, whilst in the women's sections it varied from 11 per cent, to 21 per cent. In the afternoon spell the output in all sections was always at the maximum, or very near it, in the first full hour. Then it suddenly fell to a TniTiiTnmn in the women's sections, and rose again in the next two hours and attained a secondary or an actual maximum in the last hour. The small increase of output (viz., 3 per cent.) observed in the two men's sections gives an erroneous idea of the degree of speeding up usually observed in men during the morning spell. In these same sections the mean rise observed during the April-June, 1916, observations was 17 per cent in the tool makers and 4 per cent, in the automatic machine controllers, whilst in the mixed section, which at this period was entirely a men's section, the rise was 13 per cent. Again, direct output observations were made upon 16 men (four on each of four days) engaged in the strenuous operation of sizing aluminium fuse bodies. The mean hourly output of these men in the four full hours of work of the morning spell was 93-5, 103-6, 116-3 and 113-5, or showed a 24 per cent, rise between the first and third hours. In the afternoon spell it was 112-9, 95' 8, 96-8 and 111-9, or showed similar variations to those observed in most lathe sections, though on a more considerable scale. The accident records at factory A can conveniently be split up into four main groups, as follows :— Date. Duration of Period. Average Weekly Hours of Work. 1. Nov. 2, 1915, to Jan. 31, 1916 ... 2. Feb. 1, 1916, to July 24, 1916 ... 3. July 25, 1916, to April 1, 1917 4. April 2, 1917, to i)ec. 15, 1917 Months. 3 6 8 8* and 75 hours for day shift (including Sunday labour). 64^ hours for day shift (including Sunday labour) 62 J hours for night shift. 58| hours for day shift (no Sunday labour) and 62| hours for night shift. 54| hours for day shift (no Sunday labour) and 62| or 60 hours for night shift. In the first period there was no night shift, but most of the day shift worked 77i tours per week except in the second week of each month, when they were absolved from Sunday labour or worked 69 J hoins a week^ Hence thev averaged about 75 hours a week; or a time Hke y to induce considerable ^^^^S'?^- /'^^y XtWe working these long hours for several months before the statistical period. ^°f /^^^^^^^^ ^ V^^/^^' "^.^^^^^ was a Sght shift as well as a day shift. The day shift workers put m 66J hours, ^f'^fl^^^^^^^^^Z week of Lh month they escaped Sunday labour or worked for 58| hours. The ^g^J slf gho ch^ng^ over to day shift in alteLte ^ort^^^ft -g^^as a^^^^^^^^^^ IVom August 7. 1916. onwards o n o . ->= lO . (M —• t~ . r-i M- S 05 0) ^A^ a o ^ Feb. 1, 1916, to Apr. 1, 1917. o - -li lO . ^ in . (M •-• I- I ti O Oi ka^ o . (M '-' t- w 8 05 4» • m' ^ ^ so" """t-: fi o „ -^= ■* . ^ «2 r-ies b; >a fi «g CO f^ fO «S 5^ O in o 00 eo eo gOOOSr-^ Q +3 0'*^ co-^-^-^«o CO to CO «D"^ CD t-^ 00 Oi r-l o o ^ : : >0 lO o _ ■ «,-; o o o o o=^'" +3 -+3 ^i:* O O CO^r-.-^-^ CO lO lO i-H I— I 1— ( I— 1 i-i 1— I 0 CO Co t- TJHTO ©* ft -O t>. CO CO Ifi 1-1 00. (S CO CO lO vO lO J> l- ■* vO »fi X «S CD r-l fO ■<* 't sO "O CD 00 Tfi cs rq 00 CO lO lo Ifi •* CO OS M ©:© 00 CO ■-1 1-1 •>* tfj »fi ^ CD ^-tv vp (S .00 lO Ifi Tj< •^ CO CO 02 Tfl- to 1* T* fi CO t- © vp 00 »* Oi COVfi'^TJf^CO COTjtCO'-l OJ P^ vO ^ CD. CO CO o CO CO I— 1 o :::::: :::::: .... w • . . . . • .... ,__, ■ • • • o • CO ^ : : : 'o- : : : : : g ': \ ': ■ S ' lO CO >o " ioco-cOqIZ;^ icicocococom cocqioio ® ■^ 00 oj .-( ^ Q "^ d CO ^ in lo CD t-: 00 "^ Si "^ooo-i^-t^ '"'ooooo ooo** °r!«l O.-P-i^-t^CgjCO 0-P-P-P+=i+= +s+34iO _» "•^ CD'CO'CO CO CO' ■'^CO-COCDCDCO i-HCDl— l'*^ C^S co'.eo coco.^ ^ CD CO CO CO CO CO c^ co (M co o '^ t-^i>o6oJr-i'— I i-H^cqco-^in cocot^od En Digitized by Microsoft® Oi r-1 00 00 o 00 in o in CO 00 o in CO eo CO O oo eo OS O CO CD 3.S ^ CO s.a-^ rO. a tj s S 05 so- rt TS Ph S 5 cs !=* S " Sunday labour ■w;as abolished, or in period (3) the day workers usually put in 58^ hours a week. After May 6, 1917, Saturday afternoon labour was abolished, or the day shift worked 54^ hours a week, and after October 5, 1917, the night shift worked 60 hours instead of 62J hours. Period (4) is taken to begin on April 2, instead of |Cay 7, as this date marks the drastic reduction of alcohol consumption enforced by the Government. In Table III is recorded the hourly incidence of cuts, calculated per 10,000 lathe workers per week. In that thousands of the workers at the factory were occupied in gauging and assembling fuse parts, and in 'fining the fuses, i.e., in operations at which they would scarcely ever cut themselves, it would give a very erroneous impression if they were included with the workers using lathes, drills and other machines with cutting tools. Hence the numbers of workers in the sections engaged in these types of labour were ascertained every week, and averages taken. The total number of cuts recorded in each statistical period is given at the bottom of the Table. AU the values quoted have been calculated as cuts per hour, i.e., the number of cuts dressed from 7-6 to 7-35 is multiplied by 2, and so on. The night shift worked for spells of 4, Z\ and 3 hours, but by substracting only a quarter of an hour at the beginning and end of the middle spell instead of half an hour the accident incidence for the three complete intermediate hours was determined. In the third spell the accidents were counted for a preliminary J hour, a final ^ hour (for many night shift workers began to knock ofi work 20 minutes or more before the end), and for three intermediate f hour periods. Fig. 2. — Hourly Variations of Accidents and Output at Factory A. 90 ao 70 so 40 30 20 60 WOMEN j 1 CUTS 1 t' I9i5j 1 1 f 1 r r-r-' ^.._ VJOME.N 1916 1 5 30 2S 1916 CUTS 20 IS I /V£/V " 1916 J9i7. 19161 JSlSi MEN^ WOMEN MEN I PREVIOUS INJURIES WOMEN'. 10 100 \July jA.n a 10 IZ I AM- 2 4- 5 6 7 S TIM£ or DAY 10 II IZ ll^-M.l 4-5 6 It will be seen from the Table that the accident data in periods (2) and (3) correspond closely as a rule, so in constructing the curves shown in the upper part of Fig. 2 these data have been averaged, or curves are given for what may be termed : (a) The 1915 fatigue period of 75 hours a week (day shift). - (6) The 1916 intermediate period of 64^ and SSJ hours a week (D.S.) and 62^ hours (N.S.). (c) The 1917 reduced alcohol period of 54J hours (D.S.) and 62^ hours (N.S.). Of the day shift curves, those for men correspond fairly well in the morning spell, the accidents increasing rapidly from hour to hour till they reach a maximum in the last (or penultimate) hour of full work. This maximum is 2-2 to 2-7 times greater than the number of accidents treated in the first hour. The women showed a more rapid increase of accidents than the men, their last hour values being 3 -3 to 3-5 times greater than their first hour values in periods (6) and (c), but no less than 5-3 times greater in period {a). The very rapid increase shown by the women in period (a) is due largely to fatigue, and wecan see from the curves that in the afternoon spell the accg^^|^g^lig0^t *^|^^^^^us as m periods (6) and (c). During (B 12099) ^ ^ ^ 10 the course of the afternoon speU the accidents to women remained nearly stationary during periods (6) an (c), but those to men fell gradually in periods (a) and (6), but rose gradually in period (c). r^Mimit It will be seen that the accident curves show a considerable qualitative <' 05 in I> l> O os 05 00 CO O CO 1 m t- 00 i> CO -* 00 00 fs q^ M -^ sO .-1 1> o ijq in 't fS 1?^ cilNCSi^'^ CN {N tS >H (N in in 1— lfS'*''T''7' rH (s fo fo =^ CO ■^ m »n =o CO ■<* >fi r» -i©t>r<02 oooTj^roio r-ii-iovo«o laDesooroto iooi-ioot~ T— (tH»-4 I— iT-H ^H 1— iiH^— 1 in I-H l—l CO m 2 « a 05 00 -^ C^ lO ^ »0 00 t^ ^ 'Of5CT> «:iot>t>0 oo©i-HXt- 1— t r^ CN 1^ '-i T-1 lO t^ 00 IC 05 I— t r-l in a ■ »+-l 1 1 oo .3^ g"-S.| CO ^ ri ^ <^ OiOO «aj dM.Sg ^SSS^ ooo<^=^ c^^ocdf? 1^ SS-g^ O-^-^-^CO SSS^r-* CD^«=^* ^-S 5iS-S COCO«Dcq^ ^^j^jlOlO COlOCOtMCO o'^ -gcSO-jJ tdt-^cxjoii— 1 i-ii-ii-ir4(rq c6co'^>oto E-i - o vo -H th o in in »o w t^ o O »H «S tS CO CSI ,-( rt o^ ^ ^ CO o 05 T— i rH 00 CO 3 02 a o o -H ro ic ■<* «3 fc a> f^ .H CO r-( tH tN fO © Tj< t- 1>- >* rt © rt OJ 6 rt ^ fO (S =^ !^^fOcc•^fcA in CO i i in © vO tS O c^ CO 00 t^ ic vo OS in 00 00 0^ O^ i 05 0^00 0^0^05 00 in CO 03 *> 3 P-i h- 1 ini-(©o^o»-* o5XfSoot^(M CO CO I-l r-4 in 00 iSSiSSMfS 0000r»5O^©CO 05 CO St i ID s 1 in in CO in ininco:*^-; inininin incocOQ^J^ incoeococoin f^00O5r-Hj^^ ■=? 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Tl* 00 vO 00 CO 00 to CO lo lo : iCl CO CO lO O i-l 1-1 1-i "? --' o o o"^ O 'ia -*^ -^3 O '*^ CO CO CO **^ CO CO CO CO CO O O i-i (N '^ COCOt-OOOO r-li-(i-lT-l.-l o lO (M lO O lO '^ o o* o O HJ -ti O '♦^ "^ CO 1-1 "^ ,-1 CO CO o cq CO ■<* lO CO o o o o o -(J +3 -tJ Hi -ti CO 1— I T— I r-l 1— ( CO lo ic lo in c O in vo »c rf "M Ci ^ ^ t^ O t- IC t> »C "* 00 PO © O^ CO I— i t% ^ >0 CO ^ ^ p<5 vO O t- 00 m lo 0 «5 (M O Ifi >ft Tfl •<* 00 C» tS CN M t- CO o in c<) in o m '^i^od'^oi '^ o o* o O ^-^^ -*i O '+^ "^ CO i-l ■'^ 1-1 CO CO C5 CO in CD CO t-^ oo" 00 _ o in in ^' O T— I 1— 4 I— 1 _ o o o O O -*i -t-3 -*i -+i -^ 1-1 f-1 t-l CD 1—1 in in in Oi OS 1— 1 T— I r— 1 in in in in CO CO CO m "^ CO ^ iri CD ■^0000 O -+^ 4^ -p 40 "*^ CO CD CO CD CO CO CO Ct) CO C .rH o ft H r— I CD 03 c:> ,— . 3 -S 03 m Digitized by IVIicrosoft® 17 CQ -a to -g to . ^•^ -2 5 '5 <0 'S* tS o S fH n D (fi « o . -SO o c3 Ph s 8 O O C3 O > (B ■ M ■31 .20 M , O 'Ti !=(0 8 i o" el «« --1 §^ O P- o ■ o ;o c8 a H ■SJ!.2Q r^ rs += -p a f-l fl 03 cS " Ph'-'^PrO I o o o o n a i> pi o ft O . 1^ OS > a H 00 Tt! 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M --v •* Co •! O (H O M M ■l s-g 9 i-- /^lyvi+i^y^^" 1 =>, -S =^ g u g o (B 12099) 20 nearly twice as many accidents on Thursday as on Monday, and in ttose on night shift there were 80 per cent more accidents on Thursday than on Sunday. In the men the range of variation was smaller, but it amounted to 40 per cent, in the night shift and 46 per cent, in the day shift. The frequency of the eye accidents corre- sponds with the output variations, especially so during the day shift, but evidently there must be some other agency at work besides that directly dependent on speed of production. Most of the eye accidents are due to metal tornings flying off from the objects turned, and it seems very probable that the operatives tend to bend over their work more when they are working quickly than when working slowly, and so get a much greater proportion of metal turnings into their eyes. i. v i The diurnal variations of the other accidents, which are recorded in Table VIII, call for but little comment, as many of them are not sufficiently numerous to give a very reliable result. The burns reached a maximum on the Thursday or Friday of the day shift, and on the Friday of the night shift. The sprains reached a maximum on the Thursday of the night shift, but during the day shift they reached a maximum for the men on Saturday and for the women on Wednesday. If an average be taken of the burns and sprains in men and women, it is found that their incidence corresponds well with that of output during the day shift, but during the night shift it reaches a maximum towards the end of the week, presumably because of fatigue. The previous injury oases were irregular, but as a rule they occurred in greatest numbers at the beginning and end of the week. This is what might be expected, for workers with an untreated injury would be more likely to get it seen to just before the week end break than in the middle of the week, or if they put ofE attendance till after the break was over they would be more likely to attend at the first opportunity in that the evil eSects of the injury would have been accumulating during the 38 to 41 hours when no treatment was available. It should be mentioned that the figures given in Table VIII and the two subsequent tables for " total accidents in statistical period " represent the sum of the daily accidents after they have been corrected for any differences in the daily hours of work {e.g., on Saturdays). At factory C the relative output was determined very satisfactorily from the readings of the watt- meters which were made night and morning by the works electrician between the changing of the men's shifts. Complete sets of readings of the four meters which recorded the total power consumption of the factory were available for 13 weeks in January-April, 1917, except that the power utilised on Sunday nights was not ascertainable, owing to a variable and unmeasured amount of power having been consumed on Sunday mornings. In this January-April period the men were working 69| hours a week on night shift and 57 hours on day shift, whilst the women were working 48J hours on night shift and 37^ or 47 hours on day shift. Another set of readings was obtained for a period of nine consecutive weeks in May-July, or at a time when the men and women were working the same hours, viz., 60 per week on night shift and 48 hours on day shift. These two sets of data were averaged separately, and they are recorded as percentages on Fig 7.— Diurnal Variations of Accidents and Output at Factories B, C and D. 90 90 80 //O — r 1 — ■ MEN CUTS. BURNS AMO SPflAlfJS r ~i BO 95 9S r _ -TL WOME/V ON TWO SHirrs ALL ACCIDENTS WOMEN ON THKEl SHIETS ALL ACCIDENTS afternoon MEN EYES May — Tu ly Jan. — Apr POWER LOAD AT FACTORY C L (V/GHT SHIFT Digitized by IVIicrosoft® DAY SHIFT 21 - I Oi s I i o e •g 05 00 CO 00 1| tH CO eo t- i-H to 4i 00 (» -* 50 -* Oi 01 ■I— I I— t 1— ( I— 1 ■xi t- 10 -* 'm 03 ■># CT3 t- 00 <35 C^ r^ ^ C3 0 t~ CO 1-1 >0 Oi rM H 05 -* CO ■* 45 I-i ■— 1 I-l >-l 1—1 1—1 C5 C^ ■* in CO ;a TJ o t^ r-1 1?^ Cq CO 1—1 CSI OQ ^ Oi c^ CO OJ ■* i I— H I— 1 I— t T— I 1— t r-l ^ ? tM CO O) 00 OS OS eo t- r-l t- s 03 00 C^ 1—1 to CO 05 H 1— t 1— t r~i CO 00 CO CO 10 (N CO (M CO Oi 00 -* (N Oi 05 1— 1 1— I C<1 I— I r-l " 1 • . iS «3 ^ -S O in 00 00 ■>* g|=ll CO 1-1 CO 1—1 CO r-( 1 1 00 10 10 CO r-< 1 1 in CO s r-t i-l r-4 rH r-l irq in t- fl * CO in in oo__ IN 00 in co" (m" 1 1 .) ... women ints in- nts in- 3nts in- ; \ • r cent, ats in accide accide accidi a Q(pe t.) ... scide: ual tual ctual t- 1- '9 i sprains in me: in men (per cen rains and eye ai in women (act ies in men (ac ies in women (a I— 1 _i ^ r-l ID 1= Jan.-April, May-July, s am snts : s, sp t.) ents injui njur: .s - tj Cuts, bum Eye accide Cuts, bum (per cen Eye accid' curred) Previous i curred) Previous i curred) ea p— 1 r Digitized by Microsoft® 22 the mean In the lower part of Fig. 7 and in Table IX. The curves show that in January-April neither the day or the night shift reached their maximum output until the last working day (or night) but one ot tHe working week. In May-July, on the other hand, both day and night shifts reached their maximum output three days before the end of the working week, and then deteriorated. Hence it looks as if the longer hours worked by the women, though accompanied by shorter hours for the men, caused a more rapid onset of fatigue, with its attendant reduction of output. Adequate daily output data were not obtained at factories B and D, but there can be little doubt that they would have shown somewhat similar variations to those at factory C. The accident data of these three factories are closely comparable, so it was thought best to group them together. The first group com- prises all the accidents to men except eye accidents, and the uppermost curve in Fig. 7 shows that dunng night shift the incidence gradually increased in the course of the week, and on the last i»g^* reached a maximum value which was 20 per cent, greater than the value observed on the first night. This rise was presumably due to fatigue, as the men were working very long hours, viz., 63 or more per week at lactones B and D, and 69| (for most of the time) at factory C. The day shift showed the same kind of incidence as was observed in women (for cuts) at factory A, an incidence ascribed to lack of practice-efficiency at the beginning of the week, and to onset of fatigue at the end of it. It might naturally be conjectured why the night shift did not Hkewise show any sign of the practice-efficiency factor. The probable reason is that there was only a 24-houi interval of rest between the time at which the workers ceased day shift work and began on night shift work, whilst there was generally a 48-hour interval between the end of the night shift work and beginning of the day shift work. Probably some of the numerous accidents incurred by the day shift workers on Mondays were due to a persistence of the fatigue efEects induced by the night shift work. This hypothesis is supported by the accident incidence for women. The women's data have been separated into two groups, viz., those obtained at factory B and those at factory C in May-August, 1917, when the Table X. — Diurnal Variations of Accidents to Women at Factories G. and D. Type of Accident. Shift. Total accidents in stat- istical period, Sun. Mon. Tues. Wed. Thur. Fri. Sat. Cuts, burns, Spraias and eye J accidents (per cent.) ... | Eye accidents only (actual J accidents incurred) . . . j Previous injuries (actualj accidents incurred) ... | Morning... 1,320 96-4 100-5 91-4 107-3 102-7 Afternoon 1,327 — 97-6 96-7 109-4 102-6 110-3 Night ... 1,064 85-2 85-7 93-6 112-8 106-0 116-8 Morning... 106 — 14 17 19 19 22 Afternoon 138 _ 23 23 31 21 23 Night ... 124 11 19 21 24 24 25 Morning... 156 — 39 18 24 26 25 Afternoon 130 — 22 23 22 29 20 Night ... 115 13 19 12 21 25 25 101-8 83-2 15 17 24 14 women worked two shifts ; and those obtained at factory D and those at factory C in July, 1916, to May, 1917, when they worked three shifts. The incidence of accidents for the two-shift women shows a more marked fatigue efiect during the night shift week than that observed in the men, and what is probably a persistence of this efiect to the Monday of the day shift week. The incidence of accidents in the three-shift women shows the fatigue efiect during the night shift week, but no persistence of fatigue whiBever to the Monday of the morning shift week which followed directly on it. Superposed on the morning shift curve is the afternoon shift (2 to 10 p.m.) curve. Both it and the morning curve show a slight rise of accidents in the middle of the week, probably the result of increasing speed of production. The speed of production factor is revealed clearly in the eye accident curves, just as it was in the data of factory A. The number of accidents available is too small to give a ve^y regular result, but the fourth pair of curves in Fig. 7 show that in the night shift men the eye accidents rose on Tuesday to a maximal value which was 39 per cent, greater than that observed on the Sunday, whilst in the day shift men it rose on the Fiiday to a maximal value which was 51 per cent, greater than that observed on the Monday. In the women the eye accidents were too few to yield a reliable result, but as can be gathered from the data recorded in Tables IX and X, their incidence usually difiered from that of the other accidents and approached that of the men's eye accidents. The accident data above described deal with several of the factors concerned in their causation. More information relating to the fatigue factor is adduced in a subsequent section, whilst other factors such as psychical influences and alcohol consumption are likewise discussed in their own section. The problem is one of extreme complexity, and it can never be solved completely as it is impossible to obtain data controlled by only one of the numerous factors. All the factors are exerting theic influence in greater or less degree, and it is only by the difierential method imdicated in the above discussion that probable conclusions can be arrived at. Monthly Variations of Accidents and of Output. The speed of production at all of the four factories increased considerably during the periods for which their accidents were tabulated, and such increase would be expected to augment the number of accidents. At factory A it was impossible to estimate the collective output owing to its miscellaneous character but the majority of workers were making time fuses of a standard pattern, and the conditions of production of these fuses, except as regards hours of labour, remained unchanged throughout the 25 month statistical Digitized by IVIicrosoft® 23 Sin '^I'l^^^^T ^"""^^ """.^P^n* °^ ^"^"^ *5^P^°^1 g'^^^P^ °^ *^®^« ^°'J^«^« (^i^-' o°e of men, one of youtha, Ha iT °L7°°'f ) ^^^ ascertained for the first thirteen months, and is recorded in detail in Memoranda 12 ™^;^ m ft^^ "^""^ T^^""^' °^ *^^ *"^° g™^P^ °f "^^^ ^^ ffl 60 M-l o ^ CD <^ OJ O i s g CI o a ,o ^43 ^^ to CO .^ Q -*^ a tH o CO ff^ O "S 00 to CO iO t- 05 CO lO ^ ^ to ^ CD CD COCOCO02;*J0122;222°' . . 1 1 1 I —I _^ ^^ <^mi ^^ r^ *"^ I— ( ^^ p^ r^ ^^ ^^ ^^ r~i ^^ OOOCD(MC0-^c010CO-*-*Ocgo; 0'-i. <>50000C00^CDC000t-0»C0CT)t-t-lOCDO00t-'^C*0'— iiM f-lloScDCO-*OSOOt-^(M000305a500COi-l<350lO»n-*00t-lffl'>i-CDm00 CCOi-HiOCOCOO^i— ^cOOi^^cOt^C5^^-^l— (Oa CO o CO 05i— lOOOOlOCDi— ICD-*- 00 a rD CD ^ Oi IN ^ ^ o o o -» ^ ■*^ o t- ^^§ "3 ca B , 00 eo o 00 I >0 sO o^ (M «5 1> "3 00 S SI fc S "^^ ^ ■-i <0 00 i "* CO If) ri< ro 0(NvOt- (Mlfi^eiO"^ rHfOfO'-l'-' ff^ifSvOvoo osoofO-* -*kOfs»riO i-H i-H rH I— * tH t^ 00 t- 05 00 00 CM to CO 05 05 • ■ • • o o ^ : : ::::io ioloo__: ^ ^ ■ ■ CO '--llOO 0*^0 t-:'^'^dS "7^ 'T^ 7^ (T^ c^ m^>6vi'=^. 000.-1^ 55-2oo oooo^ ^4^+24^^ coiniOT-it-i 0i-i50i-t*^ cocococOq ^^j^ioiq cOlr3eo<^5cD cdc-^OOOJi— 1 1— li— IrHrHM COCO-^iOui [- © i-l »H I> CO (N O •* Tf O r-H "* © 00 CO o 00 © © Ov ■^ 1-1 O fO l> vO vO (M 00 lO CO o © ■<* in t^ o CO vO t> ifj CS o CO rj o cq o^ © © t> ^ -H CO CO lO ■-1 ] 00 ro ro a> CM CM Tl< sC © i-l t- co es CO ® © vO CO CM O •<* kfi © t> 00- rt (S >H «okfivOvot>.-* >o»ncoio inTj(CO 0©lC©fSn CO >o ir5 in eo • _■; in CO CO ^ H^ 2 ■^ 00 Ol i-l ^ ^ 0+=-^^ CO CO CO CO CO CO CO ec5 CO ^ ^ t~ t~ 00 ai r-i T—{ in ; ; ; ; . CO • • • • • H O in lo in in o in as CM CO CO in '^ CM pi -^ in lo 8 ft in o CO crq in in " T CO , Q O o " o o o O -+3 +3 -P "*^ CO CO CO CO CO CO CO CO CO eo eo r-< r-i CM CO -^ ici CO t- 00 o 1-1 CO .-I CM eij CM CO CO CO r-^ 00 o O o Eh •^ S 5 O >d c? a> Digitized by IVIicrosoft® 33 «PPn tw'ir'^''''^ °^ °^^^^ P®'' ^^'°°° ^^°^°^y workers are quoted at tlie bottom of the Table, and it will be seen Lnat tney were usually about three times greater in the women than in the men. In the fatigue period result actually nine times greater m the women, but the number of cases is too small to yield a reliable The sai- volatile cases vary much more than the faintness cases, and in the fatigue period they were twenty- tnree times more numerous m the women than in the men. Subsequently they were only two or three times niore numerous, both m day and night shift, and so we are afforded most striking evidence of the exhausting ! t ^fii +1 ^^ °^ ^^^°^^ '^P°^ *^® women during the fatigue period. The hourly variations of cases treatea tell the same tale of excessive fatigue in the women. During the course of the morning spell the cases increasea nearly thirty-fold m the fatigue period, and seven-fold in the subsequent period, but in the men tney snowed only a three- or four-fold increase in both periods. Again, during the fatigue period the women treatea with sai-volatile were 42 per cent, more numerous in the afternoon than in the morning, but in the subsequent period, they were 6 per cent, less numerous. It IS interesting to note that in the last hour of the day and night shifts the sal-volatile cases fell off tre- mendously. In the night shift only three women were treated between 5.15 and 6.0 a.m., as compared with »b between 8 and 9 p.m., and in the day shift the number treated between 4.30 and 5.30 p.m. was not a third as great as those between 9.30 and 10.30 a.m. Presumably the exhausted workers preferred to struggle on until the end of the spell without assistance, as they knew that rest and relaxation were at hand. The faintness cases treated at Factory C were too few to yield an hourly incidence of any value, but the number of the cases, calculated per 10,000 workers per week, affords striking testimony as to the influence of hours of labour on their frequency. In the first statistical period (July, 1916-May, 1917), when the night shift men worked 69 J hours a week and the day shift men 57 hours a week, the former were treated for faintness nearly twice as frequently as the latter (c/. Table XX). From May-August, 1917, when the men worked only 60 hours by night, they did not faint so frequently as the day shift men. The women, who worked in three shifts of 37| to 48i hours during the first statistical period, fainted less frequently in the morning shift Table XX. — Faintness Cases at Factory C {Corrected to a 57 hr. Week). Men. Women. 57 hrs.. Day Shift. 69i hrs., Night Shift. 48 hrs., Day Shift. 60 hrs., Night Shift. 37| or 47 hrs., Day Shift. 48i hrs., Night Shift. 48 hrs., Day Shift. 60 hrs., Night SHft. Total cases per 10,000 workers per week- Day or morning shift Afternoon shift ... Night shift Total cases treated in statistical period — Day or morning shift ... Afternoon shift ... Night shift 22 35 53 103 24 19 10 10 61 86 82 33 37 46 101 101 34 43 than in the afternoon and night shifts, and as the ratio of accidents in the two spells of the morning shift was as 1 to r02, they appear to have had an adequate breakfast before starting work. When the women's hours of work were raised to 60 by night and 48 by day, the faintness cases increased considerably, and they were now four or five times more numerous than in the men. Hence there can be no doubt that long hours of work tended to increase the frequency of faintness both in the women and the men. It should be stated that, all the cases recorded in Table XX for men and women have been corrected to a 57 hour week. A fairly reliable index of the daily incidence of faintness and sal-volatile cases at factory A was obtained by grouping together the data for the whole statistical period investigated, and these summated figures are quoted in Table XXI. They show that in women during day shift the faintness cases were at a maximum on Monday, and kept steady at a lower level during the rest of the week. During the night shift they were Table XXI.— Daily Variations of Faintness and Sal- Volatile Cases at Factory A. Type of Case. Sex of Workers. Time of Shift. Total Cases Treated on Sun. Mon. Tu. Wed. Th. Fri. Sat. Faintness Sal-volatile. 1 Men. .., Men ... Women Women Men ... Men ... Women Women Day . Night. Day . Night. Day . Night., Day . Night.. {B 12099) 21 83 21 77 29 26 138 85 38 24 260 97 15 11 120 77 32 19 219 75 17 11 125 71 25 29 144 63 20 14 120 78 39 20 216 85 20 9 118 88 46 19 228 72 13 122 30 174 Diyilizi^U b\^ Mldrosott^ 34 at a maximum at the beginning and end of the week, and at a minimum in the middle The sal- volatile cases were very much more numerous on Monday than on any other day, and fell on Wednesday to a minimal value, 35 per cent, less than the Monday value. Probably the week end break from work is too often spent in exhaust- ing pleasures rather than in rest, and so the worker starts her fresh week in rather a collapsed condition. _ iiie night shift cases were no more frequent on Sunday, the first night of the working week, than on other nights, but this may have been partly due to the fact that most workers are inclined to slack on that night, and tHere are more absentees. , , ■■ The relationship of these medical cases to accidents is only indirect, but one may assume that a worker who felt faint or needed sal-volatile would be more likely to suffer accidents than the perfectly normal worker. Hence the variable incidence of faintness and sal-volatile cases implies corresponding va,riationsin the pro- duction of accidents, though there is no means of knowing what fraction of the accidents is dependent on these conditions. One can only say that lack of adequate nutrition is a by no means negligible pre-disposmg cause of accidents. Accidents in Eelation to Natural and Artificial Lighting. The influence of lighting upon the incidenceof accidents has been investigated indirectly by the Departmental Committee on Lighting in Factories and Workshops (Cd. 8000, 1915). They found that accidents due to " persons falling " were distinctly more numerous in the winter months than in the summer, presumably because of the less adequate lighting. Other types of accident were not so evidently affected, but by making certain assumptions it was found possible to calculate indirectly the probable accident rate per hour for artificial and natural lighting, and it was found on an average for all industries that accidents were 29 per cent, more frequent under the former conditions than under the latter. The comparisons of day and night shift accidents recorded a few pages back appear to be in flat contradiction to this conclusion of the Committee, for we saw that in all of the factories the accidents were, on an average, some 16 per cent, less numerous by night than by day. Still, this deficiency might have been due to the over- powering influence of the psychical factor and of other conditions, so it was necessary to test the question directly by the same method as was applied by the Committee indirectly. It consisted in enumerating the accidents which occurred during selected hours of the day shift throughout the year. The hours chosen at factory A were : (a) periods aggregating four hours, viz., from 7 to 8.30 a.m. and 3.30 to 6 p.m., during which the lighting is almost entirely artificial in the darkest months (December and January) ; (6) the intervening six hours, from 8.30 to 12, and 1 to 3.30 p.m., during which the lighting is for the most part natural in the darkest months. In the lightest months of the year, viz., April to September, the lighting is, with rare exceptions, natural through- out the day shift hours. The cuts occurring in these four and six-hour periods were enum.erated (as a rule) over two monthly intervals throughout the 25|^ month statistical period, and the quotients of : — Oats during hours of artificial light ,r , , t- x. \ = — ^-2 ° — X (factor to equanse hours). Cuts during hours of natural light are recorded in Table XXII. If the cuts were just as frequent in the hours of artificial lighting as in those of natural lighting, the quotients would be unity. It can be seen from the Table that they never approached this figure. In fact, they averaged only '71 in the men and -74 in the women. The reason of these low values is that, as we have seen in previous sections, the workers waste a good deal of'time in starting and stopping work, and have a low speed of production, with its accompanyipg infrequency of accidents, in the early hours of the morning shift. Hence a fair comparison of accidents during the hours of artificial and natural lighting is scarcely possible. The seasonal variations in the quotients aSord comparatively little support to the doctrine of the harm- fulness of artificial lighting. Taking a mean of the quotients for men and women, we see that between February 1 and July 24, 1916, the quotients were considerably lower than in the preceding and succeeding months, but from July 25, 1916, onwards there was little or no correspondence between lighting and accidents. There was, in fact, a gradual rise of the quotients during the greater part of this period. This was probably due to the workers wasting less time in starting work, in consequence of the reductions in the weekly hours of labour. The percentage of time in the so-called artificial lighting hours (7 to 8.30 and 3.30 to 6) when the lighting was really artificial has been calculated on the assumption that lighting up occurred half an hour before sunset and ceased half an hour after sumise (Greenwich time). This assumption does not hold at all closely at difier- ent seasons of the year, but the data quoted are sufficient for the purpose, and indicate the lack of correspondence between accidents and lighting. As far as could be judged by inspection, the lighting at factory A was not so good as that at factories B, C and D, and this conclusion receives support from the ratios of night shift to day shift accidents quoted in Table XVII (p. 30). The mean ratios varied from -85 to -94 at factory A, but from -78 to -83 at the other factories, or in other words, night shift accidents were about 10 per cent, more numerous at factory A than at the other factories. Hence it was thought to be unnecessary to work out the relationship of the accidents at these factories to artificial and natural lighting, and one may conclude that at all the factories the lighting had very little influence upon accidents, except those to the eye. It does not necessarily follow that this conclusion is irreconcileable with the aforesaid conclusions of the Committee, because their data relate to a very large number of factories spread all over the kingdom, and probably the average lighting at these factories was not so good as that at the factories investigated by me. Still, the indirect method adopted by the Committee is liable to unknown sources of error which may completely vitiate the results. For instance the temperature factor — which is discussed in the next section — may well have been responsible for most or aU of the excess of accidents which they found to occur in winter months. The ratios of night shift and day shift accidents quoted in Tables XVII and XVIII showed that eye accidents occupy quite an exceptional position, in that they were usually more frequent by night than by day. At factory A they were 32 to 46 per cent, more numerous in men, and 30 to 58 per cent, more numerous in women. At factorv B they were 11 per cent, more numerous in the women, but the men showed no greater frequency of eye acci- dents than of any other kind of accident. At factory C the men showed only a slightly greater frequency of eye accidents than of other accidents, whilst the night shift women had 9 to 29 per cent, more eye accidents than the day shift. At factory D the men had 9 per cent, more eye accidents by night than by day whilst Digitized by Microsoft® 35 el 'S « >. w r o ?»> ^ O •c o OQ o ,i!« o c3 O o o Ph m ■43 o += o M o O o r3 "S nb ^ ^ o O OQ 'H ^.SPh 45 a ID a o a o 45 P O pre 2 o PM O ■§ Pi o >— lC)O50000(M-*-*0000COC<)-* (MlOl010-*l00003>-ia3CC>COt^CO00CDt^t->'; 00 =^ 10 (B 12099) 1^ r5^ ft O CO -2 o o5 o o += "^ ^ 36 the women, though they had slightly fewer eye accidents by night, still had 20 per cent more than the mean of all the accidents. Grouping the men and women together, one may say that factory A had the mosr nignD shift accidents, factory B the least, and factories C and D an intermediate number. Ihese variations corre- sponded with the difierences in the quality of the artificial lighting, so far as it could be judged by inspection. At factory A the lights, moderate in strength, were for the most part fixed about 10 feet above floor level ana not over the work. At factories B and D very bright lights were fixed the same height above tloor levei, and usually over the work at factory B, but not over it at factory D. At factory C very bright ngUts were fixed about 5 to 6 ft. from the ground and directly over the work, and the lighting would have been mucn better than at any of the other factories but for the fact that about half of the lights had shades whicii did not properly protect the workers' eyes from di^rect beams of light. • -ut t, i-f f The seasonal variations of eye accidents for both day and night sHfts are recorded m *^®/ig'^* ^^^^ °^ Table XXII. These data represent eye accidents per 10,000 lathe workers per week, corrected to a DSf Hour week for the day shift and to a 621 tour week for the night shift. The variations are more easily grasped from the curves reproduced in Fig. 10. These curves show that in the day shift men the eye accidents to some extent rose and fell with the degree of artificial lighti ng. This lighting is roughly indicated by the reproduction of the percentage values quoted in the Table. There is a tendency for the eye accidents to increase m number throughout the statistical period, but this is due, in all probability, to the relative increase m ttie proportion of male workers employed as tool setters, with their increased liability to eye accidents. The curve oi incidence for day shift women, so far from corresponding with the lighting curve, is for the most part dia- metrically opposed to it. The accidents are at a maximum from March to July, 1916, and at a numniiun from November to March, 1917, though it is true that they show a second maximum in November-December, 1917. I am at a loss to explain this reversal of incidence, but whatever the cause it appUes almost as much to the women on night shift as to those on day shift, as can be judged from the third curve m the figure. Hence the unknown cause does not seem to be dependent on lighting. The men's night shift accidents are mode- rately steady throughout, except in the first four months of the statistical period, or show no seasonal variation similar to that observed by day. Fig. 9- -.Ej 'e Accidents in relation to Lighting. 130 1 1 MEN L_ DAY SHIFT , 5 .50 O O 40 1- 30 - - "^ DAY SHIFT a 20 " !^ in - 1 i WOMEN - o NIGHT < 40 SH irr •f. 10 -about 80 lb. in the finished condition- :Sif t^o^rit for any but ^^^£0.,^^-^^^^^^!^^^^^^^ rnufSS? aT riS^V ^d^D IX wrgft^itl; J lb., in the rough-which necessitated their Sn^moved by tackle under all cfrcumstances, so the risk of sprams was greatly reduced. (B 12099) Digitized by IVIicfysoft® 42 43 •^ >^ o 1 o 'Pm pq 03 P O o §1 a) « OQ Ph m O ^, ^ b g o e o O X X P o 03 ,0Q P-( s ! o pq o pq M O -*^ O 03 pq o 2 a> cu K! O fa "^ ft H M ;0 «D to to 05 «D I— I ■^ CO CO O CO «0 «D O °0 -^tl lO i-H t- T— 1 50 >0 t- O ■* (M lO t- CD I— * lO «D I— I .— I CT> lO t- 0 00 I— I I— I I— I C* I- -* O CO (M 1-1 to lO T— ( O t- 0 05 00 ■* (M ■* t- 00 ft f-i GC P^ Digitized by IVIicrosoft® 43 o -8 IS "S ^ a 03 §.2 02 Ph fa ® !» Ph ! O re PQ o OS 3j» CO -( -* cq r-l 00 O O t- -* as 00 oa O «D i-t -* (M r-l CD r-l 03 n3 >n ■* -* «3 00 O \.-l ■-1 »o 1— t (M O 05 fM CO CO O (N t- ■>* CO ~' I— t (M I—t I— I t- 03 03 O >o ^ »-4 t-H o o CO -1-5 Q -^ o cS I a o ti CC =0 PM TS CQ O ^ (M 00 i-l 03 T— I I— { I— * CO CO 1— i O ? CD <0 lo CO »0 CO DO •* I-l .!3 OP=lP5 soft {B 12099) .1*' 2 Digitized by IVIicrosoft® 44 The previous iniuiy cases treated at factory B were four times more numerous ia the men, and five to nine times more numerous in the women, than those at factories A and D. I think that this excessive number of cases was due largely to the carelessness of the nurses in failing to record which were first dressings and which were not, for they seemed specially remiss about this class of case ; but there can be no doubt ttiat these cases were exceptionally frequent, or the workers at this factory were more negligent m attending the dressing station than those at the other factories. They were of a lower social status than the workers at factory C, though about the same as those at factory D. . The women at factory B experienced many more cuts than at factories A and D, even after allowance is made for the inclusion of re-dressings. Probably this was due in part to the habit of moving the heavy shells by hand, but it was also a fatigue efiect, for the women generally worked a 63-hour week, ihe tact that the women in factory C suffered more cuts and other accidents in the second statistical penod than m the first, in spite of the considerable error introduced in the records of this first period through the inclusion of re-dressings, was likewise due to fatigue to some extent, but it was also dependent on the longer hours worked, viz., 54 a week, on an average, as compared with 44^ hours. The frequency of burns and eye accidents, noted in factory D, extends to factories B and C, and is dependent on the same cause. It should be stated that the day shift data of the women at factories D and C (first period), which are quoted in Table XXXI, relate to the morning shift only. t i. jti Further light is thrown on accident causation by comparing the relative frequency of the different types of accident in men and women. Table XXXII shows the ratios of women's accidents to men s accidents taken as unity, for the same statistical periods as in the preceding Table, an appropriate correction havmg been applied when the hours of work were unequal. We see that at factory A the cuts, burns and eye acci- dents were only a fourth to two-thirds as numerous in women as in men. This depended on the less risky character of their work. The sprains, on the other hand, were 47 per cent, to 88 per cent, more numerous in the women than in the men, or taking the other accidents as a standard, one may say that sprains were relatively three times more numerous in the women than in the men. The majority of these sprains were wrist sprains incurred in pushing home the lever which clamped the fuse part in the lathe. Evidently this clamp was designed for men with stronger wrists, and it would be quite easy by lengthening or otherwise altering it, to make it more suited to the weaker wrists of the women. Thereby a considerable number of these sprains would be prevented, and a by no means negligible amount of wasted time be saved. In that the work at factories B, C, and D was very similar in character, one would expect to find similar ratios between the women's and men's accidents. It will be seen that at each of the factories the men and women had nearly equal numbers of cuts. The eye accidents were generally more numerous in the women than in the men, especially at factory B, whilst the burns were two to five times more numerous in the women. These frequent burns were due chiefly to the hot metal turnings jumping out from the lathe and burning the hands, and so it might be worth while for the women to protect their hands by wearing gloves. The sprains were nearly twice as numerous in the women as in the men at factories C and D, where '9-2-inch and 15-inch shells were made, and showed a similar excess at factory B, where 6-inch shells were made. Hence it is probable that the liability of women to sprains is inherent, and cannot be altogether avoided by more suitable mechanical appliances. Nearly half of the previous injury cases are neglected cuts, and so the number of cuts treated affords some measure of the number of possible previous injury cases. We see from the table that in comparison with the cuts the women generally showed a considerably larger proportion of previous injury cases than the men. In other words, they were more negligent in attending the dressing-station when they cut them- selves. In addition to the types of accident classified and recorded, a certain number of other accidents were treated at the factories. They are divisible into two classes — (a) those connected with work at the factory, such as bruises, abrasions, trapped fingers, injuries from broken belts, metal splinters in fingers, and nails torn ; (&) those unconnected with work at the factory, such as bicj'cle accidents, cuts done at home and at meals in the canteen, and scalds from tea making. At factory A all these unclassified accidents were enumerated for a month, and when calculated out per 10,000 workers per week they came to the following totals : — Men. Day Shift. Night Shift. Women. Day Shift. Night Shift. (a) Accidents connected with work (b) Accidents not connected with work 56 31 102 46 102 54 69 26 148 156 95 TiiE Prevention of Industrial Accidents. The identification and evaluation of the various factors concerned in the causation of industrial accidents is a matter of theoretical interest, but the importance attaching to the problem depends chiefly on its practical application to the reduction or elimination of accidents. In the present study no attempt whatever has been made to investigate certain factors, such as defects of machinery and absence of guards, but with this excep- tion, I believe that most of the other factors have been . referred to, though they are very far from being worked out completely. The practical application of the conclusions arrived at has been pointed out briefly in several instances, but it is worth while to recapitulate the evidence as a whole. Digitized by IVIicrosoft® 45 In the first place, it is well to recognise that many industrial accidents, probably the majority of them, are unavoidable, and that at best one can only hope to reduce their number, and never to eliminate them entirely. Moreover, we have seen that speed of production is an extremely important factor in their causa- tion, and often the most important factor of all, so any improvement of factory conditions which increases speed of production inevitably tends to a more than proportional increase of accidents. Accidents depend, in the main, on carelessness and lack of attention of the workers, and so the more one can eliminate this lack of attention and increase the concentration of the worker upon his work, the more will accidents be reduced. As has already been pointed out, one wants to induce in all the workers throughout, their hours of labour the same mental outlook as is present in the night shift workers in the early hours of the morning. These workers have for the most part forgotten the pleasures and excitements indulged in shortly before coming on to night shift, and they have nothing but an unexhilarating breakfast and bed to look forward to. Such a mental state is impossible of achievement by the day shift workers, but something in the way of mental calm and equilibrium can be attained by stopping all conversation except that relating to the work in hand. If the workers would consent to it it would be a good plan to induce temporary deafness by plugging the ears, and so shut out the noise of the machinery, which is in itself an important cause of distraction and fatigue. Again, if it were practicable — ^though it is seldom that it can be so — it would be of value to shut out the sight of surrounding objects by separating the lathes or other machines from one another by partitions. The worker, left to himself without sounds or sights to distract his attention, could then concentrate himself entirely on the work in hand. It might be said that the monotony would be so great that nobody would stand it, but would it not be better to work for, e.g., two 3 or SJ-hour spells every day under such conditions if the worker could thereby earn as much as he does under present conditions in two 4-hour spells 1 However, these conditions are mentioned only as an ideal, which should be aimed at whenever possible. The careless habit of mind can also be diminished by stricter sobriety. There can be no doubt that the less alcohol the worker consumes the better it is for the quality and quantity of his work, and for his accident immunity. This applies especially to alcohol consumed by the day shift in the dinner hour and by the night shift shortly before coming on to work. The inclination of the day shift worker to drink during his dinner hour can be combated to some extent by establishing factory canteens, where good food is obtainable at cost price, or slightly below it. The worker would then find it more convenient to stay in the works during his dinner hour than to go home, and so would escape the temptation of drinking. The temptation to the night shift worker can be reduced by arranging that the shift start work at a time when the public houses are closed, e.g., at 6 or 6.30 p.m., as was done in factories C and D, and in factory A until October, 1917, instead of at 7.0 or 8.0, as was done in factory C (second period) and factory A after October, 1917. The production of excessive fatigue with its accompanying increase of accidents can be almost entirely avoided by choosing suitable hours of labour. It can also be combated by the introduction of seats for the standing workers to rest on occasionally when they are not actually working, and of the most suitable seats possible for sedentary workers. These and other appliances for reducing fatigue appear to have been introduced to a larger extent in America than in this country.* We have seen that even moderately defective lighting produced a considerable increase of eye accidents, and it is probable that it had some efiect on other types of accident as well, though it was not big enough to be detectable. Hence the adequacy of the lighting of a factory should be tested from time to time by an expert, whilst the eye accidents could be reduced or eliminated by the use of suitable goggles. Though it might not be worth while to insist on the majority of the workers using these goggles, it should be made a rule that they be worn by the grinders of tools, and other specially exposed workers. The importance of the temperature factor in accident causation is so evident as to need but little dis- cussion. Thermometers ought to be installed in the shops, and be consulted regularly by those in control of the heating. In my experience most engineers try to work against the laws of nature by fixing their steam pipes some 8 ft. or more above the heads of the workers. Doubtless their object is to get this apparatus out of the way of their machinery, but it means in practice that the larger part of the heat ascends in a current of hot air to the roof of the building, whilst only a smaller part reaches the workers below, and even then it reaches their heads rather than their feet. It is important that the heating apparatus should be on the floor or a few feet above it, so as to warm the feet rather than the head. With a little forethought and arrangement it would not be difficult to instal hot water radiators between the lathes and machines, and in fact this system is adopted in some of the newest factories. And finally it may be asked : To what extent would these remedial measures reduce accidents if they were adopted thoroughly ? No definite answer can be given, as the improvement produced must needs vary greatly in diSerent factories. For instance, an improvement of the temperature conditions at factory B would reduce the accidents considerably, but at factory A would produce very little eSect indeed, as the conditions were already almost as good as they could be. Conversely, improved lighting would considerably reduce the eye accidents at factory A, but not at factory B. But there can be no doubt that some reduction of accidents. is possible at every factory, though it may be only 10 per cent, or 20 per cent, in a well-managed factory, or 50 per cent, in a badly-managed one. In all large factories the factors concerned in accident causation should be worked out as fully as possible, and the efiects of the remedial measures be thoroughly tested SUMMARY. Accident data were collected at four factories, for periods of 9 to 25i months. The accidents, over 50,000 in number, were classified separately under the headings of cuts, foreign bodies in the eye, burns, sprains, and injuries incurred one or more days before they were first treated. Eye accidents aiJorded the most reliable index of accident incidence, as they were almost invariably treated within a few minutes of their occurrence, but sprains were quite unreliable. * GJ. Gilbreth, " Fatigue Study," London, 1917 : see also " Health of Munition Workers/' London, 1917, p. 64. Digitized by Microsoft® 4t) 1 Bfeed of Production. —OvA^Mi determinations at a fuze factory were made by niea^iiring the excess electric power supplied to tte various sections of the works, and verifying the results by direct enumeration of the articles produced. The incidence of accidents showed a qualitative resemblance to the output variations, and it was concluded that varying speed of production is the factor largely responsible for the day shift variations of accidents in men, and not fatigue. Even in women fatigue is of only moderate importance as a rule. ', Though the night shift output followed a similar course to the day shift output, the accident incidence, except that of eye accidents, was entirely difierent. It was at a maximum at the beginning of the shift, and fell gradually the whole night through to about half its initial value. This was due to the fact .that the night shift workers started work in a careless and excited state, and calmed down gradually during the night. At the other factories, whsre 6, 9.2, and 15 inch shells were made, there was very little hourly variation in the speed with which the operations on these shells were performed, and in correspondence therewith the hourly incidence of accidents incurred by tne day shift was fairly steady. The night shift accidents dwindled rapidly the whole night through, because of the psychical factor. The diurnal variations of accidents at the fuze factory generally corresponded with the output variations,, as both rose to a maximum in the middle of the week and declined at the end of it. The monthly variations of accidents at the fuze factory corresponded with output variations, for the- accidents increased gradually about 40 per cent., whilst the hourly output at the same time increased 30 per cent. Fatigue. — The influence of fatigue on accidents to women was strikingly shown at the fuze factory when; the operatives were working a 12-hr. day, or 75 hours a week. The women's accidents were two and a half, times more numerous than in the subsequent 10-hr. day period, but the men's accidents showed no difference. Also the women were treated for faintnsss nine times more frequently than the men, and were given sal-volatilej 23 times more frequently, whereas in the subsequent 10-hr. day period they were treated for faintness and given sal- volatile only three times more frequently. Psychical Influences. — At all the factories the night shift workers suffered fewer accidents than the day shift workers, the average defect being 16 per cent. This was not due to the output being smaller,' as at the fuze factory it was distinctly bigger by night than by dajr. It was psychical in origin, and (^-^e to the night shift, workers settling down to a calmer mental state than the day shift workers, and so becofeiing less careless and inattentive. The psychical factor is one of the most important in accident causation. Alcohol Consumption. — Indirect evidence as to the efiects of alcohol consumption on a(3cidents. was obtained. i Lighting. — Accidents due to foreign bodies in the eye were Y to 27 per cent, more numerous in the night; shift than in the day shift, though all the other accidents were considerably less numerous. This was due to the artificial lighting, as the excess of eye accidents was most marked in the worst lit factory. ; Temperature. — The temperature at the fuze factory was recorded continuously for six months by means of a thermograph. Accidents were at a minimum at 65°-69° F., and increased rapidly at higher temperatuTjes (e.g., by 30 per cent, at temperatures above 75°), and slowly at lower temperatures. Continuous records were obtained of the external temperature of the town in which the shell factories were situated, and it was found that in all of them the accidents increased considerably as the weather grew colder, and diminished as it grew warmer. In one factory the women's accidents were nearly two and a half times m.ore numerous when the temperature was at or below freezing point than when it was above 47°, whilst the men's accidents were twicp, as numerous. Prevention of Accidents. — Accidents are very largely due to carelessness and inattention, so they could be diminished by preventing the workers from talking to one another in the shops. It was foimd that the women suffered twice -as frequently as the men from sprains, and were especially.; :liable to wrist sprains at the fuze factory, as they had not sufficient strength to push home the clamping leveEi of the lathes. The women at the sheU factories suffered nearly four times more burns than the men, chiefly from hot metal turnings. Hence the sprains could be reduced by alterations of machinery, and the burns, by protecting the hands. ^ t H. M. Vernon. Cornell University Library HD 7269.M92G79 An investigation of the factors concerne 3 1924 002 909 244 ).', iiited under the authority of His Majesty's Stationery, Office By HARRISON and SONS, . PBIMTERS IN OKDINAEY TO HIS MAJESTY, ST. MAllTISr's LANE, LONDON, W.C. 2. Digitized by IVIicrosoft® Digitized by IVIicrosoft®