REVIEW of REVIEWS

The Problem of Fatigue

Its Relation to Industry Both In Its Effects on Men and Metals.

G. CLARKE NUTTALL October 1 1922
REVIEW of REVIEWS

The Problem of Fatigue

Its Relation to Industry Both In Its Effects on Men and Metals.

G. CLARKE NUTTALL October 1 1922

The Problem of Fatigue

Its Relation to Industry Both In Its Effects on Men and Metals.

G. CLARKE NUTTALL

IT IS NOW generally admitted that a proper understanding of the condition known as fatigue underlies all scientific management in the industrial world.

In writing on the subject in the Contemporary Review Mr. Nuttall tells of an interesting experiment with regard to a factory where girls were employed in folding handkerchiefs:—

“Normally each girl sat at an ordinary low table all day, folding; the only break in her occupation was when she went to take back the folded handkerchiefs and obtain fresh supplies of unfolded ones. Of course there was the usual middaybreak for dinner. The experiment began with close attention to all possible causes of unnecessary fatigue, and these were carefully dealt with; thus the table was adjusted exactly to the best height for work; the worker was also supplied with a chair of the most suitable type, comfortable and fitted to her size; further, the best possible arrangement of the handkerchiefs, both folded and unfolded, was planned. Thus all conditions which might produce unnecessary fatigue were removed. Then the investigation continued along the lines of the balancing of work and rest, and after much experiment the following routine was evolved as giving the best results. Each hour was divided into ten periods of six minutes each. For the first four of these (that is for twenty-four minutes) a girl worked sitting for five minutes and then rested one minute, sitting, so as to lose no time in beginning work again. For the next two periods (that is for twelve minutes) she folded standing for five minutes, and rested one, standing. For the next three periods (that is for eighteen minutes) she still worked five minutes and rested one, but she did both either sitting or standing as she felt inclined. For the last period of six minutes she amused herself as she pleased, walking about, etc. This gave her really seven minutes’ rest, as it succeeded the one minute’s rest of the penultimate period. This routine continued for every hour of the day except for the hour before the dinner hour and the hour before closing, when the last period was spent in work instead of rest, as there was the long rest to follow. The net result was that the worker’s output was more than three times greater than the best possible output obtained under the old conditions, and the worker ended her day with more interest and certainly less fatigue. Clearly the result justifies the trouble taken.

“The study of fatigue not only implies the attempt to eliminate fatigue, it also includes a study of its causes. The usually accepted explanation is that fatigue is a species of poisoning caused by the formation in the organism of certain waste products, such as lactic acid and carbon dioxide. With increasing fatigue these poison products accumulate in the system until the limit is reached and the activity of the organism, or the fatigued part of it, is arrested.

“It was Lord Kelvin who first pointed out in metalg the peculiar property which he called “Elastic Fatigue.’ He found that if he vibrated a particular wire time after time, the vibrations, considerable at first, grew less and less with successive stimulations, though the latter were all equal in amount. In fact, the wire seemed to grow tired with its efforts just as a man would, until at length it. only' responded feebly and with apparent difficulty. If, however, it was allowed to rest for a sufficient time it seemed to recover, and would again vibrate normally if stimulated, but again it became ‘tired’ if stimulations continued. It did not show any sign of fatigue if a long interval of rest were allowed between each stimulation.

“Now Professor Sir Jagadis Chunder Bose comes forward and, by a series of minute and fascinating investigations, carries the whole matter into a new plane. He asserts that the same laws that know

no change act equally and uniformly throughout both organic and inorganic worlds,and he claims to show in his experiments the remarkable fact that the phenomenon of Fatigue is on ‘all fours’ in the animal, plant, and mineral worlds alike.

“He experimented upon living muscle as representing the animal kingdom, and upon celery stalks, carrots, and so forth as representing the plant kingdom, and he established between them the most marked parallelism— a parallelism complete in every detail. But, mark, when he replaced either of these living organic substances by a metal wire he found the parallelism, still continued in this inorganic body. In all three cases Fatigue followed upon quick successive stimulation, a fatigue that increased with successive stimulations; in all three cases suitable and sufficient rest eliminated fatigue (if it had not gone too far) and restored the normal activity; in all three there was no fatigue if a sufficient interval of rest were allowed for complete recovery between successive stimuli. But, further, he established the remarkable fact that these responses could in all cases be exalted by stimulants, lower-

ed by depressants and abolished altogether by certain poisons. Thus sodium carbonate acted as a stimulant to muscle, plant-rtalk and wire alike, while a small dose of potassium bromide lowered response in all, and oxalic acid ‘poisoned’ both organic and inorganic matter—that is, it produced some form of molecular

“It is because Professor Bose has thus brought t he inorganic world into line with the organic that he refuses to accept the physiological explanation of Fatigue as a complete and sufficient one. There can be no question of poisonous substances being formed and collected in a fatigued wire as they are in a fatigued dog or a fatigued plant, nor can there be any physiological removal processes in' it during a period of rest. Yet there is Fatigue and Refreshment in metal as well as in animal and plant. It is for this reason that he bases the cause of Fatigue on molecular change, and the restoration by rest as molecular recovery. But herein great prohlems are involved, as indeed they are in every direction in which we approach the phenomenon of Fatigue, in animal, plant or metal.”