=Unbalanced Bodies.=--Many lines of mechanical trade afford sufficient exercise to keep the workman in fairly good health, yet few, if any, give a symmetrical physical development. The blacksmith and stone mason usually have strong right hands and arms, while the left are less fully developed. Nine-tenths of all machinists are right-handed. In nearly all mechanical industries, the right arm and the back have the larger share of the work, while the chest and leg muscles and the left arm are neglected.
=Indifference.=--Some workmen are so indifferent to physical symmetry that they are not willing to do anything to avert the one-sidedness resulting from their daily toil, even when convinced that a slight effort would correct the fault. The argument of increased health and vigor, and prolonged life, scarcely appeals to them.
Few persons are ambidextrous. Many more might use the hands with equal skill, if they would. Even so simple an operation as putting on a coat, using the wrong arm first, or buttoning a vest with the other hand, is awkward for most persons, and quite difficult to many. The best time to begin is in childhood, but, even if, when first learning the use of tools, the left hand is often made to do the work of the right, the exchange will prove restful to the overworked hand, and the symmetrical development of both sides of the body will be preserved.
A skillful teacher of music, in a private school near Philadelphia, suffered a partial paralysis of his right arm, which prevented its use for several years. This necessitated the increased use of the left hand, which resulted in its increased skill and power. Several years later, he removed to the South, where the warmer climate gradually restored the use of the right arm. By this time, the left hand had become almost as skillful as the right had been, and the severe affliction proved to be a blessing in disguise.
=Brain Workers.=--The brain workers are usually men of sedentary habits. To no class is exercise so important. Without it, some part of the human machinery is almost certain to get out of order. It may be the stomach or lungs, the liver or kidneys, the head, or eyes, or throat. There is a lack of perfect action of one or more of the parts, a clogging of the organs of digestion, or circulation, or respiration. This physical clogging at once affects the mental work, dulling the thinking powers, and often rendering their efforts futile, and making the complete cessation of labor necessary.