268° Scientific Intelligence. 
Prof. Hall in the Geology of the ~ — of New York; ce 
trough of the Hudson, traceable he sea bottom nearly 100 
Dake eek at first pies seeming to d e the eae of a 
deep continuous channel in our Western rivers, really afford no 
argument against it, fo e In ma r instances, 
ock 
projects into the old valley from the no eat side, while the dee 
channel passes under the Bien on the south’ side, on fi of 
mfeig the ig of Se aah is bui 
n of other means than 
a rock canal for passing the Louse on had it been possessed 
by steed fe rned in this enterpris 
‘I ventured to predict ‘e Gen, Wate that an old filled-up 
channel yen be found passing around the gga eg tt 
. Iwi 
laid down to fill and conceal ancient channels, but the excavation 
and the abe up of the channel ot the Tennessee—like that of the 
water in the lake basin had subsided to near its present level, Lue 
a of rosie being all silted up by the Drift clays and sands the surplus ™ 
ee y the ap? of lowest levels wherever that chanced to rodent re ity of the 
e over y point that projected from the northern extrem! 
‘sar into et — there the line of drainage was established in what 
is now kno 
ugh among the mt of the events recorded surface 
this choice of the Niagara outlet by the lake waters sn Pa at 
the erosion of the go the aceomplished since. The 
oe oe | tario, of 
vation of the basin into which the Niagara flows—the basin of Lake Ontario, 
which Queenstown Heights part of the senate to an epoch long 
