CHAP. VII.] THE ATTITUDES OF MAN. 1 97 



muscular actions on which the erect posture depends must be ex- 

 quisitely balanced against one another, and, when one is altered, 

 the rest must be readjusted in harmony with it. In the practised 

 tumbler, balancing himself on a point, or the opera-dancer, poised 

 on a single toe, we have the most beautiful examples of the precision 

 of this adjusting power. Where the basis of support is ampler, it 

 is less apparent, but not less real. 



The various parts of the body are weights, and, in the muscular 

 adjustments, are treated as such. By their symmetrical develop- 

 ment on the two sides, they are naturally balanced, and thereby 

 carried with less muscular effort. When two equal artificial weights 

 are fixed on opposite sides of the body, equidistant from the cen- 

 tre of gravity, (as when buckets are suspended from a bar pass- 

 ing across the shoulders,) the mere weight is all that the muscles 

 have to support: but, if one be removed, a corresponding inclination 

 of the body must instantly be made towards that side to counter- 

 poise the other and for this a sustained muscular effort must be 

 made in addition to that required for the support of the remaining 

 weight. Now, a part of the body on one side (say, an arm), by 

 being carried from the centre of gravity, may disturb the equili- 

 brium of weight, just as moving the weight on a scale-beam dis- 

 turbs it ; that side of the body becomes relatively heavier, and an 

 inclination towards the opposite is rendered necessary. In all the 

 changes of attitudes, similar adjustments are being constantly 

 made ; and, in general, the more accurately they are effected, and 

 the more ceconomically in regard to the outlay of muscular power, 

 the more graceful and pleasing are the movements and postures 

 themselves. 



In the associated movements of progression, or locomotion, the 

 same circumstances are observed : walking, running, and leaping 

 are but different modes in which the body is repeatedly inclined by 

 muscular effort beyond the basis of support ; and this basis brought 

 again and again, by muscular effort, under the centre of gravity. 



The movements of ordinary walking may be readily analyzed. 

 Suppose we commence by advancing the left leg. We first slightly 

 raise the left heel, and bend the left knee, to disengage the limb 

 from the ground ; throwing the weight of the body on the right 

 limb, and, therefore, inclining the body towards the right side. 

 The body is now raised by an extension of the right ankle-joint, 

 effected chiefly by the calf; the ball of the foot resting on the 

 ground, which serves as a fulcrum. At the same time the body is 

 thrown in advance of this fulcrum, and would fall, were it not that 



