J. D. Dana—The overflows of the flooded Connecticut. 505 
gravel, as usual—with the gravel, at the section I examined in 
the city, constituting the upper 25 feet, excepting 2 or 8 feet of 
sand at top. According to a levelling by Mr. H. F. Dunham 
(assistant to Mr. G. A. Ellis, of Springfield,) the height 
near its eastern limit is about 289 feet above mean sea-level ; 
and from this it gradually rises westward—or up stream—to 
286} feet. The 239-foot level is very near that of the highest 
flood about Springfield (240-245 feet); it is about 96 feet above 
modern flood-level in Westfield River. 
The proof that the waters of the flood passed the Southwick 
divide into the Farmington Valley is as follows: 
1. The upper terrace plain of the divide is not above the height 
of the upper terrace plain of the Westfield region. 
2. The Southwick Ponds, which lie along the lowest part of 
the divide, where it was passed by the Farmington Canal, are 
lower than the lower level of the upper Westfield plain. 
3. The terrrace plain of the divide may be followed down 
the Farmington Valley. ; 
On the Ist and 2d of these points I observe that the height 
of the Southwick Ponds is about 78 feet above high water in 
Westfield River, or 220 feet above mean high tide—which is 
nearly 20 feet below the lower part of the upper Westfield 
terrace. A terrace bordering the ponds carries the height up 
to about 240 feet. The level rises to the northwest over the 
Southwick plain; but there, along the railroad track, the 
height is hut 260 feet, which is 25 lower than the higher part 
of the Westfield terrace. : 
We may hence conclude that before the flood exceeded in 
height 220 feet, the flow southward had begun; and that 
as the waters rose the terrace deposits above that level were 
laid down over the divide. Since 240 feet was also the 
height of the highest terrace on the Connecticut east of West- 
eld, the waters of the overflow may have been in part those 
of the Connecticut; but it is probable that they were solely 
from Westfield River—waters which the Connecticut was thus 
deprived of; for the height of the flood over the middle of the 
Westfield basin was at least 275 feet, as shown below, the 
waters having been held up to this level (80 feet above their 
height at Springfield) in consequence, probably, of the narrow 
passage for them pelow Westfield through the Divide Range. 
As to the third point, I give the following table of hei, hts of 
the upper terrace along the valley south of the divide—t e ter- 
race plain in each case, the first excepted, being extensive. 
*T im first abrubtly, near the railroad station, and 
es tn ak aoa : the deposits are of 
_ fine earth, excepting the #0 feet whieh exe pobtiy. the top & vel: clenety 
: defined, but appears to be inticated by the pebbly The Simsbury terrace 
an elevated plain, directly west of the railroad. There is an extensive plain about 
Am. Jour. Ser, Torey Ser a X, No. 60*.—Dec., 1875. 
