TIME AND CHANGE 
that are found along the shores of the Hudson. 
The clay formed in very still waters, the sand and 
gravel in more active waters. 
This great ice-sheet not only covered our northern 
farms with rocks and stones, and packed the soil 
with rounded boulders, but it also carried away 
much of the rock decay that goes to the making of 
the soil, so that the soil is of greater depth in the 
non-glaciated than in the glaciated areas of the 
country. The New-Englander or New-Yorker in 
traveling in the Southern States may note the enor- 
mous depth of soil as revealed by the water-courses 
or railroad cuts. The ice-sheet was a huge mill that 
ground up the rocks in the North probably as fast 
or faster than the rains and the rank vegetation 
reduced them in the South, but the floods of water 
which it finally let loose carried a great deal of the 
rock-waste into the sea. 
The glacier milk which colors the streams that 
flow from beneath it finally settles and makes clay. 
Off the great Malaspina Glacier in Alaskatheoceanis 
tinged by the glacier milk for nearly fifty miles from 
the shores. Very few country people, even among 
the educated, are ready to believe that this enor- 
mous ice-sheet ever existed. To make them believe 
that it is just as much a fact in the physical history 
of this continent as the war of the Revolution is a 
fact in our political history is no easy matter. It 
certainly is a crushing proposition. It so vastly 
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