354 J. D. Dana—Glacial Phenomena 
and it is also beyond question that they finally got into the 
valley current, and were drifted back into the well-arranged 
corral. Some are now on the summit of the ridge; one of 
several cubic feet is near the “ Judges’ Cave;” but the larger 
art are a third way down the eastern slope and below this 
evel. The gneiss bowlders are mingled with those of trap and 
sandstone; and nothing shows difference in time of deposition. 
This kind of evidence is repeated again along the Mt. Tom 
ridge. Professor E. Hitchcock states in his Massachusetts 
Geological Report (p. 381) that bowlders of syenyte and granite, 
taken from the syenyte band west of the Connecticut in that 
State, are found in great numbers on the east slope of the Mt. 
Tom range all the way from Mt. Tom to Hartford ight miles 
farther south, in the village of New Britain (as made known by 
Mr. James Shepard of that place), a bowlder of zoisite and 
radiated hornblende (chiefly the former), measuring about 
2xX2%x3 feet, was turned out in grading, which must have come 
from a locality west of the Connecticut valley, in Goshen, Wil- 
liamsburg or Conway, Mass., Professor Emerson informing me 
that this region affords just such a zoisite rock, and especially 
‘the first row of high hills as you go up from the Connecticut 
valley.” (Letter of June 16, 1883.) Still farther south (20 miles 
S. of Hartford) and just east of a more eastern trap ridge (6 miles 
farther east), extending from south of Hartford to Saltonstall 
Lake, I found, near the Air-Line Railroad, a syenyte bowlder 
10 cubic feet in contents, which came from the syenyte band of 
Hatfield and Whately, Mass. (Emerson), west of the valley; 
and near it lies another twice larger, of similar general aspect, 
but not so certainly identifiable. 
Such facts prove that the phenomenon, although so remarka- 
ble, was general along the valley. They are instructive also 
with reference to the distance eastward to which the upper ice- 
stream extended over the southern part of the Connecticut 
valley region, though leaving the limit doubtful. They are 
good evidence that the two currents were moving at the same 
time. 
4. The direction over Long Island Sound. 
For twenty miles to the eastward and westward of New 
Haven bay the Sound has a mean width of 16 miles. Yet the 
greatest depth opposite New Haven bay is at present only 140 
feet. Adding the height of the adjoining hills on its sides, the 
southern side of the trough has a height of 300 to 400 feet and 
the northern, of more than twice this amount. 
*I submitted a fragment of the bowlder to Professor Emerson, of Amherst, 
and he writes that it is from the “syenite” band of Hatfield and Whately (Hitch- 
cock’s geological map), it agreeing precisely with it, containing much triclinic 
feldspar and small square érystals of orthite.” 
