208 
Labelled Boulders —Vhe Brooklyn Botanic Garden is located 
near the western end of the terminal moraine of Long Island. 
This moraine was deposited at the southern edge of the continental 
glacier that occupied the northern part of North America, during 
the last Ice Age. The southward-moving ice picked up and car- 
ried along innumerable boulders derived from rock ledges in vari- 
ous localities north of what is now Long Island. During their 
journey, these boulders were rounded and polished and, in some 
cases, aanlece with striations that still persist. Twenty-eight of 
these boulders have had their lithol gical composition carefully 
determined and compared with that of rock ledges to the north. 
By this study it has been possible to determine, with a fair degree 
of accuracy, the approximate places from which the boulders now 
in the Botanic Garden were derived by the ice. Bronze tablets, 
given by Mr. Edward C. Blum, have been placed on these boulders, 
giving their composition, and stating that they were brought to the 
Garden by the ice-sheet during the glacial period. 
— 
A similar bronze tablet is mounted on a boulder at the foot of 
soulder Hill (which takes its name from the large glacial erratic 
on its summit). The inseription reads, ‘* Boulder Hill and the en- 
tire northern portion of the Botanic Garden are part of the terminal 
glacial moraine extending from The Narrows to Montauk Point. 
This tablet was given in 1932 by the Boys’ and Girls’ Club of the 
srooklyn Botanic Garden.” 
ve 
Guide No. 7, The story of our boulders, has been prepared for 
the use of slagees:t In geography or geology, or others who may be 
interested, and may be nie ee at the Information Desk and [En- 
trance Gates. Arrangements may be made in advance for docents 
to conduct classes who wish to study these labelled boulders. 
