SAND DUNES AND SALT MARSHES 



base. Thus it were better to build one's house 

 on the shifting sand which grows and endures 

 than on the rocky hills that sink into the sea. 

 In winter among the dunes the snow and 

 sand are drifted mingled together or sepa- 

 rately, and one often finds a deep white snow- 

 bank beneath a skimming of sand, which, if 

 the snow is melting, is darker than the sur- 

 rounding dry sand. Other signs of buried 

 snow are the deep fissures formed in the sand 

 by the contracting snowbanks, and the crunch- 

 ing sound that issues when one walks over 

 the concealed snow. One of the largest snow- 

 banks, which became almost a glacier, I 

 watched during the severe winter of 1903-4. 

 This was an immense drift of snow and sand, 

 separate and commingled, encroaching on the 

 north side of the grove of pitch pines. A layer 

 of sand from one to two feet in thickness, 

 which reflected but did not so easily conduct 

 the sun's rays, so protected the snow that it 

 became compact and crystalline. On May 

 15th, this crystalline snow had a thickness 

 of thirty-eight inches at its exposed face, 

 under which, extending back to a distance of 

 three feet, was a " glacial " cavern. The sand 

 on top was cracked and crevassed, and this, 



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