ii WIND ATOMIC THEORY 195 



people there is no disturbance as one walks along 

 it ; but when a crowd meets in a narrow space, then 

 they jostle against each other, and quarrelling 

 arises. Similarly in this space which surrounds our 

 earth ; when many bodies have crowded a very 

 small portion, it is unavoidable that they should 

 jostle one another and be driven back and forward, 

 and be intertwined and squeezed. Hence results 

 wind ; the particles that were struggling have had 

 to give way, and after being tossed about and 

 remaining in suspense for a long time they at 

 length lean their weight toward one side. But when 

 a few bodies occupy a large roomy place, they can 

 neither ram each other nor be jostled by one 

 another. 



Ill 



THE falsity of this view may be inferred merely i 

 from the fact that wind by no means invariably 

 accompanies a cloud-laden atmosphere, and yet 

 more particles have gathered at that than at any 

 other time in a narrow space, where they pro- 

 duce condensation and heaviness in the clouds. 

 Besides, in the neighbourhood of rivers and lakes 

 cloud is frequent from the confinement and accu- 

 mulation of particles, and yet there is no attendant 

 wind. Indeed, sometimes such a darkness over- 

 spreads the place that the view of objects in the 

 immediate vicinity is cut off; which would never 

 happen unless numerous particles were massed in 

 a small space. Yet no period is more free from 2 

 wind than a period of cloud. Add now a con- 

 sideration of an opposite character : When the sun 

 rarefies at his rising the thick dank morning air, 



