244 BEACH GRASS 



a steep hill it is evident, even to the ground 

 walker, that powerful up-currents are formed. 

 If he stands on the edge of the cliff the loose 

 ends of his garments are blown upwards. Hawks 

 often take advantage of this state of affairs and, 

 if the up-current is strong enough, are able to 

 poise, like a boy's kite, motionless on outstretched 

 wings. Here gravity takes the place of the 

 string. Like a kite the hawk swings about if the 

 wind is gusty. If the wind drops temporarily 

 he must needs maintain his position by hovering. 

 This demonstration of the use of up-currents 

 should be plain to every one. There is no mys- 

 tery about it. The rough-kgged hawk is an 

 adept in poising in up-currents. Many a time 

 have I watched him in Labrador and Ipswich 

 poised thus. 



One of the most intimate studies I have ever 

 made of the use of up-currents by birds, was in 

 the case of gannets at the Bonaventure cliffs in 

 the Gaspe Peninsula. Against these splendid 

 cliffs some three hundred feet in height a strong 

 sea-breeze was often blowing, and it was very 

 evident even to my dull senses, as I stood on the 



