You will often hear some "live-wire" business man spoken of as a "human dynamo." He has the faculty of turning out a stupendous amount of work in a comparatively short time. How he can carry in his mind the details of so many large projects, how he can accomplish so much in actual, tangible results in many directions, how he can pull the strings of so many enterprises without getting lost in the maze of detail, is the marvel of his associates. And yet this man is never "hurried, nor flurried, nor worried." But every word and every act is straight to the point and productive of results worth while. [Sidenote: _Cool Brains and Hot Boxes_] "A cool brain is the reverse of a hot box. It carries the business of the day along with a steady drive, and is invariably the mark of the big man. The man who dispatches his work quietly, promptly and efficiently, with no trace of fuss and flurry, is a big man. It is not the hurrying, clattering and chattering individual who turns off the most work. He may imagine he is getting over a lot of track, but he wastes far more than the necessary amount of steam in doing it. The fable of the hare and the tortoise would not be a bad primer for a number of us, and the lesson relearned would not only be beneficial in a business-producing way, but it would help us in the full enjoyment of our work." [Sidenote: _Marvelous Increased Efficiency Handling "Pig"_] Progress in mental efficiency must result from the application of knowledge of the mental machine. Just as we watch the steam-engine and the electric motor to see that they are not "overloaded," so we must watch the mental machine, that no more power be turned on than can be profitably employed. This principle has already been applied to physical labor by Mr. Frederick W. Taylor in his ground-breaking studies in "scientific management." Mr. Taylor's celebrated experiments in the handling of pig-iron, by which the quantity handled in a day by one man was increased from twelve and one-half tons to forty-seven and one-half tons, "showed that a man engaged in such extremely heavy work could only be under load forty-three per cent of the working day, and must be entirely free from load for fifty-seven per cent, to attain the maximum efficiency." [Sidenote: _"Overloaded" Human Engines_] There is no reason why efficiency in mental effort should not be gauged just as accurately as in muscular activity. If there are times when your wits are not as keen, when you have not the same grasp of fundamentals, as at other times, it is because you are mentally "overloaded." It may be the result of a great variety of causes. It may be from too many hours of continuous mental effort. But the probabilities are that it is the result of vexation, worry, dissipation, or allowing the mind to be burdened with the strain of vicious, or at least irrelevant and distracting, impulses and desires. And so efficiency is lost. [Sidenote: _Scientific Management of Self_]