Athletics of To-Day 1929

202 Athletics of To-day is hollowed, the head bent back and the arms flung up to draw the chest and chin away from the bar. Lewden is, in reality, a right-foot jumper, but the negative was reversed in making the picture to preserve the sequence action of a left-foot jumper. Note two points in all these pictures: (r) The clever balance work of the arms, and (2) the way in which Simmons has kept his eyes, throughout the whole evolution, fixed upon the sighting mark attached to the crossbar. I have been at some pains throughout this chapter to point out how experimentalists, like Horine and Osbom, have been able, by the perfection of mechanical skill, to turn a natural ability to clear just over 5 ft. by sheer spring, into world's record performances of 6ft. 7 ins. and 6ft. 8 ins. respectively. But I do not know that the last word has been said even yet. To me it seems apparent that so far the attention of those who have sought to build up the mechanics of high jumping has been centred-and successfully so-upon the question of bringing all parts of the body down to the centre of gravity at a certain point in the parabola of effort. The "effort" expended by a boy of Sirnrnons's weight, which we will take at I40 lb., in clearing even a 5 ft. practice jump will probably surprise most people, but can be calculated as follows: Ki . MVI netlc energy = zG I40 X r8 2 64 = 709 foot-lb. So far he has expended this amount of energy in raising his hips to the height of the bar and has gained whatever greater height he has cleared by bringing all parts of his body down to the centre of gravity. We are now trying to find a means whereby he may raise his centre of gravity to a higher point than he has achieved so far. Reference to Picture 2, Plate 27, will show the experiment which is being tried. In this picture Simmons is kicking a bar set at 8ft. It ins., thereby developing kick and spring combined, and has brought his head to a height of 7ft. 9 ins., with his centre of gravity above the 6ft. line, and the more the kick and spring are developed together the higher must