THE SAND-DUNES OF THE ISLANDS 229 



carries the sand up a steep slope, and not far away 

 lets it pour down. 



The advance of sand is often subtle and unobserved. 

 Even when the wind is low it is moving along; and 

 by lying down on the dune one may see it coming 

 along the surface in well-defined streams. I noticed 

 this particularly on one of the islands of the outer 

 Texan coast, where the sand rivers in thousands of 

 courses were blowing a distance of a mile or more from 

 the gulf across the flat to the inner bay. They moved 

 at about the rate that a man could walk, were inces- 

 sant, and had been for centuries; yet the islands 

 retained about the same shape: the loss of sand was 

 equal to the supply. 



In 1909 Major Frederick R. Burnham and I visited 

 the sand-dunes of the delta of the Yaqui in the Gulf 

 of California, or Sea of Cortez, as it should be called, 

 and far out on an island we crossed the dunes and 

 came suddenly, in their very heart, upon a radiant 

 arm of the sea as placid as a lake. I named it after 

 my famous companion. Lake Burnham. All about 

 were peace and absolute desolation, but from far 

 away came the musical roar of the distant sea, piling 

 in before the winds that had carved these dunes into 

 things of beauty and grace. 



The sand-dunes of San Nicolas are a story in them- 

 selves. They cover and uncover the dead; they fill 

 canons, form strange shapes which float in the air 

 before they are carried away. They are eternally 

 moving and playing, like ghostly rivers, about the 

 dying island, as if the wind and sand were engaged in 

 deadly conflict, a fight to the death. Nowhere have 

 I seen mere sand twisted and tossed into the air so 



