PHYSICAL OCEANOGRAPHY OF THE GULF OF MAINE 
885 
about 3 Y 2 miles during the flood, the westerly ebb about 4^ miles. More recent 
information, however, does not substantiate this, ebb and flood being given as 
approximately equal along the axis of the Sounds in the current tables for 1924 
(United States Coast and Geodetic Survey, 1923); and the fact that considerable 
quantities of gulf weed so often drift into Vineyard Sound and through into Nantucket 
Sound in the summer season points rather to a net movement inward into the former 
from the westward. 
The returns from the line next to the east (Succonnesset Point to Cape Pogue; 
fig. 175) are consistent with a dominant set from west to east along the southern 
side of Nantucket Sound, because all but one of the recoveries were to the eastward 
of where the bottles were set out — 9 of them from points along its northern shores as 
far as Chatham; 1 close to Rose and Crown Buoy outside the sound, about 11 miles 
east of Nantucket Island; 1 from the southeast shore of Nantucket; and 1 from the 
coast of Rhode Island. Bottles from all parts of the line stranded along the north 
shore, and the drifts that went out of the sound were from both ends of the line (the 
bottle picked up near Rose and Crown Shoal was thrown out closest to Succon- 
nesset) . This suggests that all traveled eastward at first, as would naturally happen, 
as they were put out one to two hours after low water; but this first flood, running 
at an average rate of about 1 knot, can only have carried these bottles 4 or 5 miles 
east. 
It is possible, of course, that the bottles that went fiom this line to the eastern 
side of Nantucket and to Rose and Crown Shoal passed out of the sound via the 
Tuckernuck Channel; but the more direct route eastward is the more probable when 
these drifts are studied in connection with the line put out across the eastern end of 
the sound. 
Fourteen bottles from this line were recovered, 6 of which (set out abreast the 
channel between Nantucket and Monomoy) made long journeys to Long Island, 
New York, and New Jersey, while 8 bottles set out behind Monomoy Island were 
picked up along the coast near by, between Harwichport and Monomoy. This divi- 
sion, and the fact that the only bottles from this line that were recovered within 
the sound were those just mentioned, makes it fairly certain that the bottles that 
made the long journeys did not go westward through the sound, but drifted east- 
ward out of the latter at first and then veered clockwise to the southward and so 
around Nantucket by the same general route followed by bottles set out off the 
mouth of the sound in 1922 (line B, p. 880), and so continued westward, paralleling 
the coast, to the points where they were finally picked up. 
This division between the drifts followed by the bottles from the southern and 
northern parts of the line clearly reflect a tidal difference. All were put out two to three 
hours before high water; but while the first group was carried eastward by the flood 
and out of the sound, the second group was caught up in the current flooding north- 
ward into Chatham Roads. The fact that so many then stranded there, instead of 
coming out again with the ebb, and that so many bottles from the line next to the 
west were found along the northern shore of the sound, shows that the bight inclosed 
between Monomoy Point (with its submarine extension in Handkerchief Shoal) and 
the south shore of Cape Cod is the site of a subsidiary anticlockwise eddy, as might 
be expected from the trend of the coast and from the contour of the bottom. 
