204 Shadowings 



and eddyings, all strengthening or weakening 

 according to the tide-rise or tide-ebb of the city's 

 sea of toil. But the attraction of the greater 

 spectacle for us is not really the mystery of 

 motion: it is rather the mystery of man. As 

 outside observers we are interested chiefly by 

 the passing forms and faces, by their intima 

 tions of personality, their suggestions of sym 

 pathy or repulsion. We soon cease to think 

 about the general flow. For the atoms of the 

 human current are visible to our gaze: we see 

 them walk, and deem their movements suffi 

 ciently explained by our own experience of 

 walking. And, nevertheless, the motions of the 

 visible individual are more mysterious than those 

 of the always invisible molecule of water. I 

 am not forgetting the truth that all forms of 

 motion are ultimately incomprehensible: I am 

 referring only to the fact that our common rela 

 tive knowledge of motions, which are supposed 

 to depend upon will, is even less than our pos 

 sible relative knowledge of the behavior of the 

 atoms of a water-current. 



Every one who has lived in a great city is 

 aware of certain laws of movement which regu- 



