The Physiologist in Industry
I
THE human machine is the oldest machine in industry, and in its fundamentals it is doubtless the same now as when it was first put to work. The men of Mentone, the Palaeolithic CroMagnons, with their flint blades and drills, their ingenious many-barbed bone harpoons, their needles and chisels; the Egyptians who cut and hauled and lifted huge stones into the enduring pyramids — all these human machines ingested and acquired energy from proteins and fats and carbohydrates, just as we do to-day. They, like us, inhaled oxygen and exhaled carbon dioxide; they, too, needed vitamines, although they did not know it. Their hearts beat then as ours do now; they, too, possessed a blood-pressure, and varied it according to the needs of their organs; their glands secreted; their brains directed their muscles; they spurted or loafed on their jobs; they were ambitious or indifferent; they labored and slept; they loved and hated; they sickened and died — as do the factory hands of to-day.
And along with this conservation of physiological and psychological processes, it is a curious fact that, although in the recent centuries mankind has learned much about the parts of the human body and how they work, singly and in correlation, advance has been far less in exact knowledge of how the machine as a whole behaves. We know more about hygiene and sanitation than did our forefathers; but of the best methods of getting the most out of our biological machinery we still know far too little. And this lack is especially striking when we put our machines into factories.
The case is very different with the industrial machines of wood, of brass, of bronze, of iron or steel. One need not here dwell upon the obvious, which is almost miraculous. New ways of doing the old things have been devised, and new things to do. Each year millions of dollars are expended in improving the old and constructing the new, and searching after ways of performing industrial operations more cheaply and more effectively. These industrial machines have been dev ised by the human machine, and they supplement and specialize its work; they even surpass their makers in power to do specific things. Yet the human machine is lord of them all. When it ceases to work they stand idle.
It is not strange that industry has been slow in learning and introducing ways of improving the efficiency of its workers. In the past, here and there, small attempts were made to solve the problem; but they were not deep, and did not indicate how big and hard and important the problem was. And then the war came, with its unprecedented demands upon human energy, and the physiologists and psychologists began to invest igate, —in England, in America, in France, — to find out how human beings in the factory actually work and how their efficiency may be increased. The seven years of continuous research that have now elapsed, coupled with what came before, have accomplished much. It has become clear that industry in the past has muddled through this part of its job, and that now the more exact, more intelligent, methods of science must be used. A great step in industrial progress will be taken when we learn the human machine adequately and learn how to use it.
The human machine differs from other industrial machines in several important particulars.
In the first place, it can perform a great variety of work. Then, too, it has a large capacity for training. But, with all its possible work and possible training, most human machines possess innate qualities, difficult to analyze, but becoming less and less difficult to detect, by which they can do certain kinds of work more readily than other kinds; and thus the possibility arises of classifying the workers and assigning them to appropriate jobs. In the past this has usually been a rather haphazard affair. The employment manager, or his representative, looked the applicant over, asked him a few questions, and ‘sized him up’; but to-day, from careful study of the various occupations and their specific requirements, tests have been devised for stenographers, typists, computing and other machine operators, toolmakers, inspectors of v arious manufactured products, moulders, mechanical engineers, salesmen, telephone operators, clerical workers, and others. Such tests endeavor to determine, and express in mathematical terms, the fitness of the applicant for the specific work in question, The validity of many of them has been demonstrated by rigid trials. They are constantly being improved and added to. No tests are infallible; but there can be no question of the superiority of a test that has been intelligently devised, wisely given, and successfully employed in numerous cases, over the old method of ‘hire and fire.’ Vocational guidance, by means of such tests, is gradually overcoming skepticism, prejudice, and opposition, and is aiding innumerable human beings to find their proper setting.
Another peculiarity of the human machine is that it cannot work long before becoming fatigued. Fatigue is usually manifested by certain characteristic feelings — a disinclination to continue work, a feeling that greater effort is required, a desire to work more slowly. If the person refuses to be guided by these feelings, the original pace may be kept up for a considerable time; but, if he yields to them, the pace slackens, and gradually less is accomplished. Sooner or later he must yield to them, unless his machinery is to be seriously injured. Thus, fatigue is a signal of ultimate danger to the mechanism.
Biologists have devoted years to the investigation of fatigue, the ways in which it manifests itself, its causes, and means for its detection and alleviation. A few years ago an ingenious German doctor thought that he had found the secret, by the discovery of a fatigue toxin, — like bacterial toxins, — which produces its own antitoxin. This antitoxin was claimed to do wondrous things when taken internally, in tablet form, or even when sprayed by an atomizer into the air of a schoolroom — and, if a schoolroom, why not a factory? With the characteristic foresight of his industrious race, the discoverer protected himself by patents in Washington and elsewhere; but, unfortunately, the laboratories do not confirm the claims of the Patent Office.
With continued investigation the problem of fatigue still eludes the searcher. As each new effort is made to solve it, what appeared simple years ago seems only to increase in complexity. I am inclined now to believe that there is nothing specific about the condition which, for convenience, we call fatigue; that it has no single, or even simple, causative factors; but that the fatigued body is in a very different chemical, and perhaps physical, state from that of the unfatigued body, and that to restore the non-fat igued condition there are needed profound chemical, and perhaps physical, changes.
As to the manifestations of fatigue, and tests for its presence, we are almost equally in the dark. It is simple enough under the easily controlled conditions of a laboratory, where one can take apart a living mechanism and make its organs and tissues work separately, to demonstrate the progressively diminishing working capacity of active cells. A muscle fatigues rapidly; a nerveending fatigues rapidly; a nerve-fibre resists fatigue. But with the fatigue of the body as a whole, the problem of its analysis becomes infinitely more intricate.
There are certain differences in the chemical activities of the resting and the working body; but definite amounts of chemical change have not been correlated with definite amounts of work accomplished. The same is true of physical changes. Studies of the mental capacities of individuals in the fresh and the fatigued state have been legion; but different investigators have obtained such different results, and a positive finding by one has been contradicted so often by a negative finding by another, that the subject is now a maze of bewildering uncertainty.
But, notwithstanding the difficulties, — which will, of course, not be forever insurmountable, — there are indirect ways of demonstrating objectively the fatigue of the human body. Compare, for example, its diurnal curve of work with that of a machine of metal. With the latter, when once the power is turned on and the pace is set, the work goes on uniformly from hour to hour; the output of each succeeding hour, and of the final hour of the spell or the day, is no greater and no less than that of the first hour; in other words, the diurnal curve of work is a horizontal line, neither rising nor falling from beginning to end.
With the human machine the form of the curve depends on the nature of the operation. It cannot always be plotted. For example, I have no means of expressing graphically my own curve in writing this article for the Atlantic, although Trollope, with his two hundred and fifty words every quarterhour, rain or shine, might possibly have done so for Barchester Towers. But where, as in many factory operations, the day’s work consists of a series of similar neuromuscular actions, repeated over and over again, perhaps hundreds and thousands of times, and the product can be measured exactly in number or weight of similar pieces produced, plotting the diurnal curve of the individual is a simple matter.
If the operation is what may be called a ‘machine ‘ operation, where the pace is set by the lifeless mechanism and the living being is merely an accessory, he, too, can work along a horizontal line. But, if it is a ‘physiological’ operation, when the worker is free, within limits, to choose his own pace, and when he so uses his forces that, as he leaves the factory at night, he can honestly feel that he has accomplished a real day’s labor, his curve of work from hour to hour reflects his physiological state.
As physiological states differ, curves of work differ; nevertheless, certain curves are habitual. Such, for example, is the diurnal curve of many operators performing dexterous handwork in a certain American brass-factory, which maintained a ten-hour day of two shifts, equal in lengt h and separated by an hour for luncheon. The day’s work began well, and the output of the first hour was at no mean figure. But it was surpassed during the second hour by nine per cent, and a still higher figure, the maximum of the day, was reached during the third hour of the morning. Then the work fell off, slightly during the fourth, more rapidly during the fifth, hour; and when the workers went to their luncheon, they were accomplishing scarcely more than at the beginning of the morning spell. Their curve of work for the forenoon thus showed a rise up to the day’s maximum, followed by a fall.
These two phases, which are very common, are usually ascribed, the first to the favorable action of practice, the second to the unfavorable action of fatigue. Since, however, practice and fatigue are two antagonistic factors, continually present, it might be more correct to say that the rise of the curve represents the preponderant action of practice, the fall the preponderant action of fatigue.
The luncheon hour gave an opportunity for the workers to take food and to rest. But while they were recovering from their fatigue, they were losing the beneficial effect of practice. The curve of the afternoon spell repeated the main features of that of the morning, rising at first and then falling; but each hour, except the first, was characterized by less production than the corresponding hour of the forenoon; while the final, and tenth, hour was marked by a great fall of the curve, representing the least work of the day. Thus, if we are to judge from the output, not only was fatigue indicated in the latter part of each spell of five hours, but there appeared greater fatigue in the afternoon as compared with the morning, and the greatest fatigue of the whole day in the final hour of work.
In those operations of this factory which made special demands on the muscles of the workers, and where fatigue might perhaps be expected to be more pronounced than in dexterous operations, the fall in both spells was greater, and the terminal lowest point was lower, than in the dexterous curve. In fact, the work of the final hour of muscular work amounted to only sixty-three per cent of that of the maximum. The luncheon hour was characterized by a marked recovery of working power — an excellent demonstration of the restorative action of food.
This same factory, which was engaged during the war in the manufacture of explosive shells, maintained at the time a night-shift of twelve hours, and the curve of the night-workers was also plotted. It, too, revealed practice and fatigue effects during both spells, but its most striking feature was a tremendous and sharp fall at the end of the shift, between 5 and 6.40 A.M., almost no production, indeed, occurring during the final forty minutes.
II
The output of the human machine, unlike that of the non-living mechanism, is increased by occasional rests. The benefits of the luncheon hour are obvious; but many facts demonstrate that other resting-periods are not, in the end, mere lost time. The big burly stupid Schmidt, carrying heavy iron pigs to railway cars, was compelled by his foreman to sit down and rest for a few minutes after every ten or twenty pigs, and his day’s record of loading was increased from twelve and one-half to forty-seven tons, the accomplishment giving a great boost to the so-called ‘scientific management’ of his day.
It must be allowed, in this instance, that other factors besides periodic rests may have contributed to Schmidt’s achievement. By introducing a tenminute recess into the forenoon and the afternoon spell of a ten-hour day, experienced American munition-workers increased their average day’s total output in different operations by one, three, eight, eighteen, and even twenty-six per cent. Both American and British observers report other instances of the improvement following the adoption of enforced brief resting-periods.
It is not only the school child who benefits from recesses: it is the adult as well. The human machine abhors monotony, as nature abhors a vacuum. It must have change. If it has been sitting, it must stand; if standing, it must sit. It must gossip and laugh and dance and take food and read newspapers — anything that will turn nerve and blood-currents into new channels; that will make overactive cells rest, and torpid cells active. The English cup of tea might be established in our American factories with profit. The most advantageous number and duration of industrial recesses and the ways in which workers should use them probably differ in different occupations and with different workers. However these details may be decided in individual cases, observations seem to justify the general conclusions, that no one may be expected to work advantageously for a period of five continuous hours without a break, and that systematic recesses are superior to those that are taken voluntarily.
III
The working of the human machine is affected by various physical factors in its environment. One of these is air, and the modern science of ventilation shows what qualities good air possesses. In extreme cases air may be rendered impure by poisonous chemical substances produced in manufacturing operations, which men and women cannot long breathe without detriment. But under ordinary circumstances the bad air of crowded rooms is not due to chemical contamination, but to a rise of temperature, a rise of humidity, and a lack of motion. The human motor, like other motors, generates much heat, and must be continually air-cooled if its temperature is not to rise to a detrimental degree.
I once placed a healthy young man in a chamber large enough to enable him to sit comfortably, and supplied him with abundant, but still, air at an average temperature of one hundred and two degrees, Fahrenheit, and an average relative humidity of ninety-one per cent. In two hours his bodily temperature had risen from ninety-eight and six tenths to one hundred and four and four tenths degrees. At the end of a three hours’ inspection of the various processes in one of our leading steel plants I found that my own temperature had risen from normal to one hundred and two degrees.
Exposure to air of a high temperature and high humidity is debilitating. Professor Scott and I observed that the muscles of animals which had been subjected for six hours to an atmosphere of an average temperature of ninety-one degrees, and an average relative humidity of ninety per cent, were capable of performing only seventy-six per cent of the work of other animals living at sixty-nine degrees of temperature and fifty-two per cent of humidity.
In certain Welsh factories manufacturing tin-plate, the amount of production was observed to show a seasonal variation, being greatest in the cool winter months and least in the summer; but the summer reduction was markedly less in those factories which were equipped with good ventilating systems. In an American automobile factory, sixty-eight departments were found to have undesirable physical conditions. The records here revealed that the requests of the operators for transfer from one job to another were most numerous, and the labor turnover wars greatest, in connection with those operations that were characterized by heat, smoke, fumes, and other features of bad air. The number of daily absences from work in this air was exceeded only in those operations that involved excessive noise. The number of headaches reported to the company’s hospital, while greatest where eyestrain was prevalent , was only slightly less where bad lighting occurred. Thus the human machine is affected unfavorably by certain physical features in its environment. To secure its highest efficiency these should be eliminated.
IV
The human machine is quite capable of wasting its forces. To sit instead of stand is often allowed by the nature of the job, and is physiologically economical; but sitting in a strained position is not economical. There is always a best bodily position for each worker for his occupation at the moment, and it should be discovered and established. To adapt chair and bench to his needs is a simple help toward the efficiency of his mechanism. A change of bodily position is often economical. As I write these pages, I usually stand at a high desk; but occasionally I sit or move about.
The human machine, too, often wastes energy by making needless, unproductive motions. These may be due to the placing of the working-materials in an inconvenient position. A bricklayer, for example, can build his wall more rapidly, and with an expenditure of less energy for each square yard, if his bricks are not thrown indiscriminately on the platform on which he is standing, — an arrangement which necessitates his stooping over to pick up each brick, — but are piled on a bench at the height of his wall and convenient to his hand.
Even when working-materials have been most advantageously placed, the worker often — perhaps it may be said, usually — makes needless motions. How to reduce these to the least possible number, to confine his movements as far as possible to those that are actually productive, has been the endeavor of ‘time-and-motion study’ for nearly fifty years, ever since Frederick Taylor began to tamper with the traditional tactics of the steel factory. The simplest method of discovering unnecessary motions is just seeing them; but it does not take the discoverer very far, and it may lead him astray. Observation and comparison of the ways of the best workers in performing the same operation; analysis of the whole cycle of motions into its constituent parts; the use of the stop-watch in measuring the duration of the parts and the whole, were early employed with advantage. But more scientific methods were demanded, and the increasing complexity of the aids to analysis may be best indicated by a list of the varieties of their apparatus arranged in chronological and neological order; kymograph, cinematograph, cyclegraph, stereocyclegraph, stereochronocyclegraph, and autostereochronocyclegraph.
I trust that the reader will not be repelled by these names. Chemistry can do worse. The man of science is rarely a linguist, and the language of science can be far from mellifluous. It is not necessary to explain these instruments. Suffice it to say that they have all been employed in recording the motions made by the fingers, hands, arms, or other parts of human machines, in a great variety of industrial operations, for the purpose of enabling an observer to follow through a complex motion — human motions are usually complex — from beginning to end, and to consider how it may be simplified, how needless movements may be eliminated, and how the machine may be taught to confine itself to those that are really essential to the end in view. The graphic curve made by one of these instruments from an untrained worker may appear, for all the world, like a seismographic record of a terrestrial disturbance; yet a few weeks of training and practice in more economical methods may change it into a graceful succession of a few rhythmic lines, representative of a few effective neuromuscular efforts.
The usual result of time-and-motion study has been to increase the output of the worker. Thus, by elimination and combination, the traditional eighteen motions made by the mason in laying a brick were reduced to one and three quarters; and, instead of one hundred and twenty, he could lay t hree hundred and fifty bricks in the hour; four hundred dozen pieces of cotton cloth were folded, each with ten or twelve motions, where formerly twenty to thirty motions were required for each of one hundred and fifty dozen pieces; a girl was able to wrap with paper the same number of boxes in twenty, which she had previously wrapped in forty, seconds; a clerk, whose motions were reduced from t hirteen to six, was able to open two hundred, instead of one hundred, letters in an hour; and numerous similar examples might be cited. Even when output is merely maintained and not increased by the modified method, there is an advantage, in a lessened expenditure of energy.
There are dangers in the elimination of unnecessary motions. There is the danger of excessive speed and drive and over-fatigue. There is the danger of spoiled work. There is the danger of assuming that the fewest motions necessarily constitute the most effective method. There is the danger of assuming that all workers can most profitably perform a given operation in exactly the same manner. There is the danger of crushing initiative. But all these may be avoided by an intelligent, sympathetic director, who realizes that a misuse of the newer method will, in the end, defeat the object of improving the efficiency of the human machine. Time-and-motion study, properly conducted, will greatly aid this object.
V
A paramount distinction of the human machine, in comparison with machines of metal, is that it is the seat of instincts and emotions, and its reaction toward the call of its work is modified by them. During the war American munition factories displayed patriotic posters on their walls, and records of their previous week’s high production, and invited stirring speakers to give five-minute talks to their workers, in order to stimulate a still greater output. I once watched a lively game of football between teams of healthy, ruddy, English munition girls during the noon hour, and I could not doubt that the afternoon work of both players and lookers-on was bettered by it.
There is, no doubt, a swirl of conflicting emotions within a striking workman’s body, when the pleading of his wife and children for food turns him toward the factory, and at its door he is greeted by the call of ‘scab’ from his fellows. A worker may have ambition to excel, and yet loyalty to his mates and the demands of his union may induce him to stereotype his production at the level of the mass; but, if the temporary stoppage of the machinery threatens a loss of his piece-wages for the day, he may spurt to more than double his usual pace. It was the custom in a certain American factory to stop work for a quarter of an hour every Thursday, to distribute the weekly pay-envelopes. This markedly increased the output — in one operation thirty-nine per cent — either before or after the interruption.
The tradition of the least work and the largest pay may be strong with the worker. The labor turnover in the department of a hated foreman is apt to be large. Suspicion and distrust of employers, whether justified or not, are often habitual. In the many phases of what has unfortunately been named ‘welfare work,’ some workers find real mental and physical blessings, while others see only paternalism, an invasion of private rights, and diabolical devices for drive. To one worker sabotage is justifiable, while another respects his tools as he does himself. One may be a dull plodder, capable or incapable; another may be emotionally unstable, quick to respond to good and to bad influences.
Instincts are mainsprings of human industrial action, and a sagacious analyst has classified them into instincts of workmanship, ownership, self-assertion, submissiveness, curiosity, play, pugnacity, sex, the parent, and the herd. Wisely directed, they may become forceful aids to efficiency; led astray, they may disorganize and obstruct. It is probable that emotional instability is one of the potent factors in the industrial unrest that has followed the war.
VI
These peculiarities of the human machine, which I have been picturing, are not merely academic matters, of physiological and psychological interest only: they throw light upon some of the vital problems of labor.
What, for example, should be the length of the working day? — a mooted question for more than a hundred years, since English manufacturers demanded sixteen hours, and English humanitarians contended that a man’s factory was not his castle, into which the king could not enter. It is a fact beyond doubt that, from the standpoint of accomplishment by the human machine and its conservation, the day should tend toward brevity rather than length. It is, indeed, true that, if large production in a brief time is the object sought, it is physically possible to quicken the pace, drive the machine dreadfully, and force it to turn out more goods. So can a flivver be rushed at a reckless rate; but the wise rarely drive it so.
Most employers of labor naturally desire a continued large production. A few examples may be cited to show how this has been obtained in specific instances. In 1900 the famous Zeiss Optical Works of Jena reduced its working-day from nine to eight hours, without lowering its rate of piecewages, with a resulting increase of 16.2 per cent in the hourly, and of 3.3 per cent in the daily, earnings of its men. The shortening of the day of the bituminous coal-miners in Illinois, from ten to eight hours, was followed by an increase of the average amount of coal mined daily by each man from 2.72 to 3.16 tons. At the Engis Chemical Works, in Belgium, it was found that the same workers at the same furnaces with the same tools and raw material produced in seven and one-half hours as much as they had been producing in ten hours. The employees in an English boot-and-shoe factory maintained at forty-eight weekly hours their former output of fifty-five and one-half hours — an achievement that could hardly be ascribed solely to the free cup of tea provided by the company at ten in the morning and three in the afternoon.
During the war some carefully controlled measurements were made of the relation between actual working hours and the output of workers engaged in various occupations involved in the manufacture of fuses for explosive shells. When the weekly hours of men sizing fuse-bodies were reduced from 58.2 to 50.4, the week’s total output was increased nineteen per cent; when the hours of women turning fuse-bodies were reduced from 66 to 47.5, there was an increase of total output of thirteen per cent; and when the hours of women milling screw-threads were cut from 64.9 to 48.1, total output fell by the trifling amount of one per cent. It is significant that, of all these three operations, that of sizing fuse-bodies, in which there was the greatest improvement in production, was the one in which the physiological element was most prominent, while in that of milling screw-threads, with its slight loss, the pace of the worker was largely dependent upon that of her milling machine.
Here are two authentic instances of what happened when overtime was added to a customary day’s work. While the employees of the Zeiss Optical Works were still doing their regular nine hours, one hour was added, in view of the coming Christmas rush of trade. There was an immediate increase in production, and hopes were high; but within a month hopes and production had had a grievous fall, the former to a level not determinable, the latter to that of the original nine-hour day. So, too, the British tin-plate millmen, who, when transferred from eight-hour to six-hour shifts, increased their hourly output markedly, dropped again to their previous record on a return to the longer hours.
These instances suffice to illustrate the peculiar ways of the human machine in its relation to length of labor. With a machine of soulless steel, decreased hours mean decreased production; with a machine of flesh and blood, decreased hours, within limits, mean increased production. It is difficult to make people believe this seeming paradox. Long hours maintained by a worker mean, in the end, one of two things: either a slow pace, or overfatigue of his organism. If a slow pace occurs, the object of long hours is defeated. If over-fatigue occurs — but, first, let us see what over-fatigue involves. It was shown in the laboratory long ago that fatigue does not increase in arithmetical proportion to the increase in work done, — twice the work, twice the fatigue, — but that additional work imposed upon an already fatigued individual is disproportionately more fatiguing, and a disproportionately longer time is then required for recuperation. The human machine is, it is true, constructed with a large margin of safety, and can often endure for a considerable time more than the usual calls on its working capacity. But, if over-fatigue occurs, the certain result of a maintenance of long hours is the laying aside of the machine. Yet change of personnel, labor turnover, is one of the most costly features of industrial administration.
These fundamental physiological facts are overlooked too often by employers of labor, especially when emergencies arise. Then the first thought is for more working hours. A rush of orders, perishable fruit, too few hands — familiar situations met by familiar procedures. Great Britain made the time-honored mistake in dealing with her factory workers in the early days of the war, when she imposed long hours, overtime, and Sunday labor, and defeated her commendable purpose of turning out the greatest possible quantity of munitions in the shortest possible time. I think that I am not claiming too much credit for my professional brothers when I say that it was largely the physiologists who convinced the British Government of the fatal error of its ways, and brought about a return to a more rational way of utilizing the vast possibilities of its human machines.
When we turn from the general conclusion that the working-day of the human machine should tend toward brevity rather than length, and face the question of its actual duration, our difficulties increase. I cannot conceive that a twelve-hour day of continuous labor continuously repeated can ever be physiologically economical. Nor can I conceive that a six-hour day would ever make excessive physiological demands upon those who are physiologically fitted to maintain their places in industry. Vernon, an English physiologist of wide experience in the study of factory laborers, and of wide knowledge of the present status of industrial physiology, has suggested as a tentative scheme that, from the point of view of maximum output, the working-day of the textile worker, whose occupation is largely connected with machine operations, might be fixed at nine or ten hours; that of the worker who combines manual skill and strength with machinery, at eight hours; and that of such a manual laborer as the coalminer, at seven hours.
Whether this be accepted or not, I think it is fair to maintain that, in endeavoring to decide upon the proper length of the day, consideration should be given, first, to the physiological aspect of the matter. The integrity of the physiological mechanism should first be assured. It results from this that, from the physiological point of view alone, the endeavor to establish a working-day of universal applicability, appropriate to all occupations and all individuals, is an unscientific procedure. Whether it might seem best, from the economic and the sociological standpoints, to equalize the dissimilar physiological days, is hardly a question for the physiologist.
VII
It was Dr. Johnson, I think, who said that deviation from nature is deviation from happiness. In its long history, industry has been guilty of many deviations from nature. To me there is always something uncanny in the sight of men Hocking to the factories when darkness is coming on. I have never known a night-watchman who was habitually jovial. It is true that an appreciable part of the work of the world is performed at night; and yet nature seems never to have intended man to make of himself a nocturnal animal. His bodily temperature, which has its source in the chemical changes within his tissues, falls steadily through the night, and reaches its lowest ebb in the early morning hours; and even the night-watchman, who has spent years in his lonely service, cannot force the clinical thermometer to behave differently.
Exact measurements of the output of day-workers and of night-workers on similar jobs show that the latter habitually produce less — two, six, ten, twelve, and seventeen per cent in different groups under observation. Where workers shift every fortnight from day to night, and again from night to day, the depressing effect of the night’s labor is more evident in the second week of the night-shift than in the first, and is even carried over into the subsequent first week of the day-shift.
I have already mentioned the enormous fall during the morning hours in the output of men working through a twelve-hour night. These are the least productive hours of all. The early morning is the time when nature asserts herself. Of a squad of seventyfour of these men under the scrutiny of an observer, two thirds were found sleeping at different times between 3.30 and 6.30 A.M. Operations that required twelve seconds for performance in the evening, when the gang was fresh, now required more than seventeen seconds. Continuous night-workers lose more time from their work than continuous day-workers. Night-workers are less strong muscularly than day-workers; but we do not yet know whether this is a consequence of their endeavor to turn night into day. The attempt to turn night into day is, however, essentially unphysiological. The human machine rebels against it, even if the human will may not.
VIII
The considerable body of knowledge concerning the ways of the industrial worker, which has now been accumulated, and from which I have drawn freely in the present paper, has been contributed by several countries, and the greatest advance has been since the Great War began to make its excessive demands upon human energies. The unparalleled call for munitions of all kinds early began to draw tense the nerves of Englishmen, and to make them wonder whether industry could carry on to the end. This doubt, too, was expressed later by a clear-thinking Frenchman, who wrote: ‘A nation finds itself to-day in danger of defeat, not because it does not know how to fight, but because it does not know how to manufacture.’
In 1915, Mr. Lloyd George, then Minister of Munitions, was induced to appoint a Health-of-Munition-Workers Committee, composed of men of science, leaders in industry, both employers and employees, and public servants; and a systematic scientific investigation of many of the urgent problems was begun, leading to numerous valuable reports and recommendations. Toward the close of the war the Committee was replaced by another body, the Industrial Fatigue Research Board, also under government auspices and with similar functions, at whose head was Professor Sherrington, Oxford physiologist, eminent for his investigations into the nervous system, and now advanced to knighthood and the presidency of the Royal Society. In 1921 there was incorporated a third body, the National Institute of Industrial Psychology, founded ‘for the application of psychology and physiology to Industry and Commerce,’ whose director is Dr. Myers, for many years Director of the Cambridge Psychological Laboratory. These bodies, led by Great Britain’s leading men of science, have been ably assisted by men prominent in British industry; money has been contributed; skilled investigators have been employed; the factories of the United Kingdom have been widely opened for study; and a considerable body of valuable literature has already been issued.
In 1917 the United States Public Health Service recognized the industrial stress of the war, and with the aid of American men of science organized an intensive and comparative investigation of two of the leading factories, which were busy with war industries, and together were employing nearly fifty-thousand workers. The main report of this research has been published, and subsidiary reports either have been already issued or are still in progress. In the United States, too, contributions have come from private and from university laboratories, and from the laboratories of certain factories where the counsels of men of wide vision prevail.
France also has, in Paris, its investigative body, the Institut Lannelongue. Spain has, in Barcelona, its Institut d’Orientació Professional. Even before the enemy had left Belgium, plans for the some-time reëstablishment of her industries were beginning to be formed, and a commission was sent to this country and England to learn of the methods of industrial organization in use and in prospect. Italy, Sweden, Canada, and Japan are also making inquiries as to the possibilities of the new ways of looking at the industrial worker. In all of these activities, whether investigative or informational, there have been, as in all things scientific, free international coöperation and exchange.
But achievement imposes obligation. Finality is never reached in scientific research. The investigator is lost who closes his mind to change. No science, except that of the charlatan, springs full-armed from any head. The progress that has been made has been gratifying, but the most gratifying feature of it all is the vision that it brings of future progress. Of all biological organisms, the human body is the most difficult to investigate; yet I am confident that at last we have found the right path to the way of the worker; that in a few years the fashion in which the employer deals with his living machines will be fundamentally changed; and that again it will be shown, as it has been shown so many times in human affairs, that ‘science is the great liberator.’