II. LOCATION AND PHYSICAL FEATURES OF THE AREA 
STUDIED. MODE OF DETERMINING AND MAPPING 
THE DISTRIBUTION OF PLANTS, THE PHYSIOG- 
RAPHY, AND TIDE-LEVELS. 
1. LOCATION, CONSTRUCTION OF MAP, MODE OF DISCOVERING AND 
RECORDING THE POSITIONS OF PLANTS. 
Cold Spring Harbor is on the north side of Long Island, 30 miles east of New 
York City. The Inner Harbor, with which we are concerned here, opens by a 
narrow channel from its northeast corner into the Outer Harbor. The two 
harbors are separated from each other by a spit of sand and gravel, locally 
known as the “ Spit ” or “ Sand Spit,’ the former of which names we shall use 
for this barrier. The Outer Harbor opens into Long Island Sound 5 miles north 
of this Spit. The studies here recorded have been confined chiefly to the Inner 
Harbor, which, because of its size, its relatively quiet water, and its proximity 
to the Laboratory has proven a very satisfactory area for study. 
The map of the harbor here used (plate 1) has been built up from an enlarge- 
ment of a map prepared in 1901 by H. R. Codwise. In the course of our work a 
series of contours, above and below the water-level, and many details in the 
topography, wharf-lines, etc., have been added to the original enlargement. 
As a means of accurately locating points of importance for the topography 
of the harbor, or in plant distribution, several lines of range-stakes were driven 
in the bottom and on the shores. The main north-and-south axis in our map 
is along a line running due north for 2,800 feet from a large pile at the 
southwest corner of the Inner Harbor. ‘This pile is about 3 feet to the 
shoreward of the wharf-line and 90 feet south and east of the nearest corner of 
_ the Biological Laboratory. Stakes were driven in the bottom of the harbor at 
intervals of 200 feet along the length of this line. Eastward from the same 
pile a second line of stakes, also 200 feet apart, ran over the bottom of the 
harbor and then across the north end of the estuarial marsh south of the 
harbor. ‘These main north-and-south and east-and-west axes were laid out by 
a small surveyor’s compass. When tested later by a professional surveyor their 
directions were found to be correct within a few minutes of arc. The distance 
between stakes was measured with a considerable degree of accuracy, by means 
of a steel tape or a piece of steel wire exactly 200 feet long. This was a 
somewhat difficult proceeding, since nearly all the measuring on the north-and- 
south axis had to be done from boats. But by hooking a loop at one end of the 
wire over a nail in the center of the last stake set, and then placing the center 
of the other stake exactly at the other end of the wire, a considerable degree of 
accuracy was attained. The total distances measured correspond closely with 
those indicated by Codwise and those on the United States topographic map. 
All distances mentioned in this paper, in noting the position of plant-groups 
or contours, are in feet, since this is the unit used in the United States 
topographic map and in the tide-tables published by the Coast and Geodetic 
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