A LIMNOLOGICAIv STUDY OP THE FINGER LAKES. 
539 
LAKES OF THE SENECA BASIN. 
Seneca and Cayuga Lakes (pi. cxiii, cxiv). — These are the largest and deepest lakes 
of the group and closely resemble each other in surface dimensions. Seneca Take, how- 
ever, is nearly 56 meters deeper than Cayuga, the ratio of the maximum depths of the 
two lakes being i : 1.42. The mean depth of Cayuga Lake is even less, being to that of 
Seneca in the ratio of i : 1.63, and their volumes have about the same ratio. The map 
shows a large area of shoal water at the north end of Cayuga Lake, which is not found 
in Seneca Lake. The outlet of Cayuga Lake, also, passes at once into the extensive 
Montezuma marshes, another indication of the flat condition of the country at the 
north end of the lake. 
The topography of the shores of these lakes is very similar. The country is relatively 
flat at the north end. (See fig. 2 as well as the plates.) The shores rise toward the 
south and for the southern half or two-thirds of their length, the lakes are bounded by a 
steep slope, often precipitous at the bottom, which reaches in places 100 meters or 
more in height. Above this steep slope there is for much of the way a more or less 
definitely marked shelf, and above this there is another rise to more considerable isolated 
heights. There are no high hills which crowd down toward the water as is the case in 
most of the other lakes. The lakes have the appearance of a broad, quiet river, with 
steep banks of nearly uniform height. Their scenery is therefore rather tame as com- 
pared with that of the other major lakes; but at the southern end of both lakes the 
entering streams have cut deep gorges which are famous for their beauty. The lateral 
tributaries of these lakes are larger than those of the smaller ones and points built out by 
them into the lakes are correspondingly larger. At the south end of each of these lakes 
there is a flat or delta built out into the water by the large streams which enter from the 
south. 
The authorities which we have consulted give the area of Cayuga Lake as slightly 
larger than that of Seneca, but our very careful measurements, both from the Cornell 
maps and those of the United States Geological Survey, reverse this relation. The 
following table shows the details for each lake : 
Table II. — Areas of Cayuga and Seneca Lakes. 
Authority. 
Area in square miles. 
Cayuga. 
Seneca. 
66.8 
Cornell maps 
United States Geological Survey maps 
66. 0 
66.3 
® Rafter, G. W.: Hydrology of the State of New York. New York State Museum Bulletin 85, 1905, p. 216. 
The transparency of these lakes, as measured by Secchi’s disk in 1910, was 5.1 
meters for Cayuga Lake and 8.3 meters for Seneca. 
These lakes are part of the canal system of New York, and their outlets are 
controlled by the works at the entrance of the canals into the lakes. 
