een 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_]

The "human dynamo" is a man who long ago learned the lesson of
scientific management of his own mental forces. He does one thing at a
time, and does it the best he knows how. He directs the whole power of
his mentality to the one problem and solves it with accuracy and
dispatch. There is no more of a "load" on his "gray matter" than there
is on that of the fretting, fuming, finger-biting fritterer, but every
pound of steam is spent in useful work.

Look at the victim of St. Vitus' dance. There you have an illustration
of wasted energy. And it is mental energy, for every muscular movement
represents the release of thought power. The mental lives of most men
are equally aimless. They are lives of ceaseless activity producing
nothing.

[Sidenote: _Psychological Causes of Waste_]

Sometimes it happens that a man is not working to advantage because of
some defect in his physical make-up. He may have defective vision or
some peculiarity of hearing that renders him unable to respond as
quickly as he should to the demands made upon him. If these defects
are ascertained, it is usually a simple matter to correct the defects
by mechanical means or readjust the relative duties of different
persons so tha