to do in a day; that is, to study the tiring effect of heavy labor upon a first-class man. Our first step was to employ a young college graduate to look up all that had been written on the subject in English, German, and French. Two classes of experiments had been made: one by physiologists who were studying the endurance of the human animal, and the other by engineers who wished to determine what fraction of a horse-power a man-power was. These experiments had been made largely upon men who were lifting loads by means of turning the crank of a winch from which weights were suspended, and others who were engaged in walking, running, and lifting weights in various ways. However, the records of these investigations were so meager that no law of any value could be deduced from them. We therefore started a series of experiments of our own.
Two first-class laborers were selected, men who had proved themselves to be physically powerful and who were also good steady workers. These men were paid double wages during the experiments, and were told that they must work to the best of their ability at all times, and that we should make certain tests with them from time to time to find whether they were "soldiering" or not, and that the moment either one of them started to try to deceive us he would be discharged. They worked to the best of their ability throughout the time that they were being observed.
Now it must be clearly understood that in these
