MUSCLES THAT TIRE EASILY SHOULD BE SAVED.—­It must be remembered that all work should be so arranged that the muscle that changes the position or shape of the eye or the size of its pupil should not be operated except when necessary.  Care in planning can oftentimes standardize conditions so as to relieve these and other muscles, which grow tired easily, or transfer this work to other muscles which are not so easily tired.

Not only do the reactions from such standards require less bodily effort, but it also requires less mental effort to work under methods that are standardized.  Therefore, both directly and indirectly, the worker benefits by the standardization.

REST FROM FATIGUE IS PROVIDED FOR SCIENTIFICALLY.—­Scientific Management provides and prescribes rest for overcoming fatigue of the worker more scientifically and economically than he could possibly provide it for himself.  Weber’s law is that “our power of detecting differences between sensations does not depend on the absolute amount of difference in the stimuli, but on the relative amount."[11] The additional fatigue from handling additional weights causes fatigue to increase with the weight, but not in direct proportion to the extra weight handled.  When the correct weight of the unit to be handled has been determined, the additional weight will cause fatigue in quantities greater in proportion than the extra weight handled.

REST PERIODS ARRANGED FOR BEST GOOD OF WORK AND WORKER.—­If possible, rest from fatigue is so arranged as to interfere with work the least.  The necessary rest periods of the individuals of a gang should come at that period of the cycle that does not cause any allowance to be made for rest in between the performance of the dependent operations of different members of the gang.  Such an arrangement will enable the worker to keep a sustained interest in the work.

WORK WITH ANIMALS SHOULD BE STANDARDIZED.—­The necessity for standardizing work with animals has been greatly underestimated, although it has been done more or less successfully in systems for construction work.  For work with horses and carts, the harnesses and the carts should be standardized and standards only should be used.  The instruction card dealing with the action, motions and their sequence should be standard to save time in changing teams from the full to the empty cart and vice versa.  While standardized action is necessary with men, it is even more necessary for men in connection with the work of animals, such as horses, mules and oxen.  The instruction card for the act of changing of teams from an empty cart to a full cart should state the side that the driver gets down from his seat to the ground, the sequence in which he unhooks the harness and hooks it up again, and the side on which he gets up to his seat in the cart.  Even the wording of his orders to his horse should be standardized.

While this book will deal with the human mind only, it is in order to state that a book could be written to advantage on training the horse by means of a standard man-horse language and a standard practice of their combined action.