116 REPORT OF COMMISSIONER OF FISH AND FISHERIES, 
PRELIMINARY REPORT UPON THE CURRENT OBSERVATIONS IN LONG ISLAND SOUND. 
By BE. E. HASKELL. 
The observations for this discussion were made during the summer of 1890, from 
the U.S. Steamer Fish Hawk, during a joint investigation by the U.S. Commission of 
Fish and Fisheries and the U.S. Coast and Geodetic Survey, for the purpose of study- 
ing the condition of and the circulation of the sea through Long Island Sound, 
For a knowledge of the tides that traverse the Sound we placed at New London, 
New Haven, and Willets Point—practically at each end and the middle—a self- 
registering tide gauge. With the tide gauges in operation, we made from the steamer 
Fish Hawk a series of current observations, occupying therefor current stations 
which in location give a cross section near each end of the Sound; a current station 
about every 10 miles in the longitudinal axis of the Sound; and a current station on 
each of the dumping-grounds of the towns of New Haven, Milford, Bridgeport, Nor- 
walk, and Stamford. 
In illustration of the tides of the Sound, the mean establishment of Block Island 
and that of Sandy Hook are about the same, namely 7" 31™ and 7" 35™, respectively. 
There being but about ten minutes difference in time, due to difference in longitude, 
it is practically high water at both places at the same time. From these places 
the tide wave that causes high water travels by two different channels, the Block 
Island branch through Long Island Sound from its eastern entrance, and the Sandy 
Hook branch passing through New York Harbor and East River into the Sound from 
its western entrance, and give to this inland channel a compound tide. 
From our observations, which confine us to the reach from New London to Willets 
Point, we find it is high water at New London (the mouth of the Thames) 9° 47™, at 
New Haven (Light-House Point) 11" 17™, and at Willets Point 11" 24™ after the 
moon's transit. The opposite phase of the tide takes place at New London 3" 31", 
at New Haven 5" 03", and at Willets Point 5" 45™ after the moon’s transit. These 
figures give for the duration of rise 6" 16™, 6" 14™, and 54 39™ for New London, New 
Haven, and Willets Point, respectively; and, for the corresponding duration of fall, 
62°08, 65 10™, and 6h 45™, 
The distance from New London to New Haven, measured ona central line through 
the Sound, is 56 nautical miles, and the distance from New Haven to Willets Point, 
measured on the same course, is 48 nautical miles. From the mean establishment of 
these points, givenaboye, and the corresponding distances between them, it appears 
that the tide wave travels from New London to New Haven in 1" 33", or at the rate 
of 23 nautical miles per hour, while it travels from New Haven to Willets Point in 
10, or at the rate of 288 nautical miles per hour. This remarkable difference in 
speed of the wave in these two reaches is undoubtedly caused by the interference of 
the two waves that have arrived on the scene by the two different routes. It is tlie 
meeting-ground; or, to be more explicit, the reach from Hell Gate to Stratford Sho. 
is where the energy of these waves, traveling in opposite directions, is spent. 
An interesting feature in the tide of the Sound is the vertical motion of the water 
that takes place. Mean sea level at all points throughout this water course is at 
the same elevation, and might be represented by a straight line so far as the present 
discussion is concerned. At New London the average rise of the tide is 2.6 feet, or 
it has a semi-amplitude in its oscillations above and below the straight line repre- 
senting mean sea level of 1.3 feet. At New Haven the average rise of the tide is 6 
feet, or its semi-amplitude is 3 feet. At Willets Point the average rise of the tide is 
7.3 feet, or its semi-amplitude in reference to the line is 3.65 feet. These figures 
shew that with every tide the water surface of the western portion of the Sound 
is alternately made a hill and a hollow when compared to the water surface in 
> 
