cA 
11 
Boston Harbor and the atlases of Plymouth апа Norfolk Coun- 
ties; but certain features, especially the marshes, drainage lines, 
drumlins and other drift reliefs have been greatly modified in ac- 
cordance with original observations. The aim has been to com- 
pile the best obtainable data, rather than to preserve a uniform 
degree of accuracy, and undoubtedly some parts of the map are 
much more reliable than others. Even in the absence of con- 
tour lines, it exhibits some of the more important relief features, 
the kames and drumlins being clearly distinguished ; while the 
hydography, including the shore-lines, ponds, streams, swamps 
and marshes, is represented with unusual completeness and ac- 
curacy ; and it shows in addition the general structure of the 
hard rocks, and especially the relations of the granitic masses to 
the sedimentary and voleanic deposits. The Nantasket area, the 
elucidation of which is the special object in view, forms the central 
part of this first or general map, which thus illustrates its topo- 
graphic and geologic relations to contiguous districts ; while the 
second or special map, on a scale of 600 feet to the inch, permits 
of much greater detail. 
No good or even approximately accurate topographic map of 
all that large part of the Nantasket district west of the County 
Road has heretofore been published, and it has been necessary to 
devote considerable time and labor to the preparation of a suita- 
ble basis for the representation of the ‘geologic features. I 
am particularly indebted to Mr. Wm. M. Beaman for the sub- 
stantial accuracy of the western area, between the railroad and 
Weir River Bay, and for a general triangulation of the entire 
district from Planter’s Hill to Green Hill and Black Rock ; and 
to Mr. Gordon H. Taylor for the contour lines upon nearly the 
entire map excepting the western area.! 
The map of Rocky Neck is based upon the plan of a land 
survey kindly furnished by Mr. John R. Brewer; and the 
coastal area, from the steamboat wharf to Green Hill is re- 
! Messrs. Beaman and "Taylor have made a careful study of the topography of this 
section as students in the Department of Civil Engineering in the Massachusetts 
Institute of "Technology. 
t 
