7 o THE ADVENTURES OF A NATURE GUIDE 



surface. It is a good mattress to sleep on; often 

 I have rolled out of one of these tree-top beds with- 

 out discovering the tumble till morning! 



Snowslides, landslides, and other factors often 

 pile up embankments of debris, and these form 

 large windbreaks whose shelter allows trees to grow 

 in places formerly windswept and inhospitable. 

 Trees at timberline are eternally vigilant and 

 promptly seize every new opportunity or opening. 

 One spring a landslide on the slope of Mt. Clarence 

 King piled a shipload of stones on a windswept, 

 treeless flat. A few years later several dozen spruce 

 were growing up in the leeward of this chance-made 

 shelter. 



But slides or other forces occasionally remove 

 shelters behind which a forest front was formed. 

 Or they place an obstruction which changes the 

 course of the prevailing winds. Snowslides oc- 

 casionally cut an avenue down into a forest, which 

 exposes the trees on the edges of the new avenue. 

 Or an old stretch of forest front is sheared off by a 

 slide. With the hardened front ranks removed, 

 the less hardy trees thus exposed are slashed and 

 shot to pieces by the cutting edges of the prevailing 

 gales. 



One day I came out upon a long, hedge-like 

 growth of trees extending down the slope. Here 

 the high, sand-flinging winds blew from west to 

 east. A lone boulder about six feet in diameter 

 at the west end of the hedge had sheltered the first 



