He made the discovery sitting in the draught of an electric fan. He looked up, made a mental note; and next morning he moved his office ``comforter'' out to the head of one file of machines. The draught tangled the goods under the seamstresses' hands at times, but the half dozen girls within range showed a decided increase in production over the day before and over operators at other tables. He had found his remedy for the summer slump. Within a week he had installed a system of large overhead fans and an exhaust <p 167> blower and saw his production figures mount to the winter's best average. From careless, indifferent workers, on edge at trifles and difficult to hold, his force developed steadiness and efficiency. Not only was the output increased twenty per cent over previous summers, but the proportion of spoiled work was considerably reduced. One of the women who had been a subject of the first day's experiment struck close to the reason of her greater efficiency in her off-hand answer to his inquiry. ``It was a pleasure to work to-day. It was so comfortable after yesterday you just forgot the other girls, forgot you wanted to rest, forgot everything but the seams you were running and the fact that it was a big day. I'm not near so tired as usual either.'' _A successful day is likely to be a restful one, an unsuccessful day an exhausting one. The man who is greatly interested in his work and who finds delight in overcoming the difficulties of his calling is not likely to become so tired as the man for whom the work is a burden_. <p 168> The experience related summarizes the experience of every worker who has studied, either on his own initiative or at some other's instance, the effect upon output secured by the removal of distressing or displeasing conditions from the workroom. The man who has been engaged in intellectual or manual labor finds himself more or less exhausted when the day's work is done. The degree of exhaustion varies greatly from day to day and is not in direct proportion to the amount of energy expended or the results attained. A comparatively busy day may leave him feeling fresh, while at the end of a day much less occupied he may be utterly ``dragged out'' and weary. Some men habitually find themselves fatigued, while others ordinarily end the day with a feeling of vigor. These contrary effects are not necessarily due primarily to disparity in the amount of energy spent or to unequal stores of energy available. The discrepancy in many instances is due to diverse attitudes toward the work or varying <p 169> degrees of success which has attended the work. Pleasure secured in and from work is the best preventive and balm for tired muscles and jaded brains. Dislike or discomfort, on the other hand, adds to toil by sapping the strength of the worker.