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of the Island, near Astoria and Long Island City, there are no 
outcrops of bedrock on Long Island. At the Brooklyn Botanic 
Garden bedrock is 400-500 feet below sea level. The large 
boulders, therefore, afforded the most logical material for a rock 
garden on Long Island, and quantities of them were used for that 
purpose, 
In connection with other grading in what is now the Native 
Wild Flower Garden, and north of the Japanese Garden, it be- 
came desirable to construct two retaining walls, and some of the 
boulders were used to good effect for that purpose. 
The boulders have also been of value to the Garden in the con- 
struction of ten dams in the artificial brook that runs through the 
garden, in the construction of boulder bridges over the brook, as 
mountings for bronze tablets, and otherwise. 
A Puzzle to Solve 
But how did it happen that there came to be such quantities of 
these large boulders in this locality? Geology teaches us that the 
various features of the earth’s surface have come to be as we now 
find them by a series of gradual changes, and are therefore sub- 
Fic. 3. Glacial boulders uncovered during grading operations in Brooklyn 
Botanic Garden, North Addition, 1913. Site of present Rose Garden and 
Lilac Triangle. (1314 
