WALKING TROTTING. 65 



Several years afterward this same man left the baths at 

 Loueche at two o'clock in the morning, and reached Cha- 

 monix- at nine in the evening, having walked a distance 

 equal to about seventy-five miles in nineteen hours. In 1844 

 an old guide of De Saussure, eighty years old, left the hamlet 

 of Prats in the valley of Chamonix in the afternoon, and 

 reached the Grands Mulets at ten in the evening, then after 

 resting some hours he climbed the glacier to the vicinity of 

 the Grand Plateau, which has an altitude of about 13,000 

 feet, and then returned without stopping to his village. 



We will cite in addition the performance of a man from 

 Thun, who walked in September, 1867, a distance estimated 

 at forty Swiss leagues in twenty-three hours, representing at 

 least thirty-four hours of walking for ordinary travellers. 



Running differs from walking principally in the fact that 

 at a given moment the body leaves the ground, and passes 

 through space in the same manner as a projectile. The 

 body is inclined more forward, and the centre of gravity is 

 lower than when walking. The lower limbs execute the 

 same alternate movements as in the first mode of progres- 

 sion; but at the moment when the right leg leaves the 

 ground and commences its demi-oscillation, the left, which 

 is bent and only touches the ground at the extremity of the 

 foot, pushes rapidly forward, and with sufficient force to 

 throw the body upward and forward, and the two legs oscil- 

 late together during an instant, then the one which left the 

 ground first falls before the other on the point of the toes. 

 The body has made a spring, and the same manoeuvre takes 

 place alternately on each side, and the result is a succession 

 of springs which constitute running. 



Trotting is running when the impulsion forward is not so 

 strong, and the movements are less rapid, which renders it 

 more applicable to uneven ground, where it is necessary to 

 choose the place where the foot is to be placed at each step. 



The greatest attainable speed for a man is, according to 

 the brothers Weber, seventeen miles in an hour; but if this 

 speed has ever been maintained for one hour, which is 

 doubtful, it could not certainly be continued much longer. 

 The maximum of speed attained in the gymnasium of 



