Nor do most classes of mechanics fare much better. Take the heavier kinds of skilled labor. The blacksmith rarely uses one of his hands as much as the other, especially in heavy work, and often has poor legs. Indeed, if he has good legs, he does not get them from his calling. The stone-mason is equally one-handed--one hand merely guiding a light tool, the other swinging a heavy mallet. Nine-tenths of all machinists are right-handed. And so on, through the long list of the various trades where severe muscular exertion is requisite, there is a similar uneven distribution of the work to the various parts of the body, the right arm generally getting the lion's share, the left but little, the back more than the chest--or, rather, than the front chest--and the legs having but passive sort of work at best. Puddlers and boiler-makers, plumbers and carpenters, coopers and smiths, shipwrights, carriage-makers, tinners, and all who follow trades calling for vigorous muscular action, not only constantly work one side more than the other, but many of their tools are made, purposely, right-handed, so that they could hardly use them with the left hand if they wanted to. As to those whose work is more delicate, saddlers and shoe-makers, mill-hands and compositors, wood-turners, tailors, jewellers and engravers, and nearly all the lighter craftsmen, learn their trade with one hand, and would never venture to trust any of its finer work to the other. In short, take the mechanic where you will, in the vast majority of instances his right arm and side are larger and stronger than his left, and quite as often his vocation does little or nothing to strengthen and develop his legs. The fact that most of these men have active work for some of the muscles, with enough of it to insure a good appetite, combined with inherited vigor, makes them often hearty men, but it leaves them unequally developed. When they get into the gymnasium, they are usually lacking in that symmetry, ease, and erectness which they might all along have had, had they but used the means. The result, then, of overworking one part of the body at the expense of the other, especially in heavier mechanical labors, and of too little vigorous action in the lighter, tends to make the average workman more prone to disease. Were there uniform development, and that daily vigorous exercise which would stimulate the dormant parts of the man's body, it would add to his life and usefulness. But how is it with the sturdy laborer? He can hardly be liable to the same defects. His work certainly must call into play every muscle of his body.