2. Necessary fatigue, which results from work that must be done. The new method, which enabled this same bricklayer to lay three hundred and fifty bricks per hour, where he had laid one hundred and twenty bricks per hour before, did not eliminate, and did not expect to eliminate all of the fatigue accumulated in the working day. The bricklayer at the end of the day, by reason of motion study devices, laid more brick, but was nevertheless much less tired. Experimental work in his case was carried to a high degree of perfection, because he was recognized as a splendid type of efficient brawn. The Problems of Fatigue Study. The problems of fatigue study are, then, four, which may be stated in very simple terms: 1. To determine what fatigue is unnecessary. 2. To determine what fatigue is necessary. 3. To eliminate all unnecessary fatigue possible. 4. To distribute the necessary fatigue properly, and to provide the best possible means for speedy and complete recovery. The Methods of Fatigue Study. The methods used must rest on a scientific basis. These methods are the same for the expert and for the man making his first attack on the problem. They are as follows: 1. Record present practice, make an accurate and complete account in writing of what is actually being done. 2. Decide in what sequence things are to be measured, and put them in such shape that they can be measured. 3. Apply accurate measurement. 4. Determine standards synthetically from the measurement, and make such changes in practice as will make it conform to the standard. 5. Compare the new standard practice with the old practice. Determine exactly what improvements have been made, in order to be able to predict the line along which new improvements must lie. This is the standard method of attack of measured functional management. It can be the more successfully applied to fatigue study in that the results can be checked at every point by the results of motion study, which bear a constant relation to them. Emphasis in Fatigue Study. Any such study as this demands an emphasis upon accuracy. The man making the study must have a strong desire for finding and writing down the facts. He must have willingness to submit every aspect of the problem he is studying to the test of accurate measurement. Along with this desire for facts must go a realization of how the facts are to be used. Fatigue study is a constructive study. It builds up. It uses such terms as “elimination,” but its fundamental aim is conservation, and this conservation includes adding to those things which make life worth while. The desire to act as a force for betterment must be the incentive that makes the man doing fatigue study ready to record and face the actual facts. A Work for Every One.