104 The American Geologist. February, 1895 
depth of about 35 I'eet and an average depth of not more than 
25 feet.* This seems to iniply a larger volume than the pres- 
ent Niagara at Buffalo. But it is very probable that the nar- 
row, rocky place ten miles east of the present divide, as men- 
tioned by Mr. Gilbert, f was the original col, and that the 
volume of the river may be more truly measured by it. 
In the fourth paper the Nipissing beach is described in its 
extension along the north shore of lake Huron and the south 
shore of lake Superior to Duluth, a distance of over 600 miles. 
Its development throughout is so characteristic that it is read- 
ily recognized wherever seen and is not liable to be confused 
with any other beach. Nearly all the points of identification 
in the north are close to a line connecting Duluth and North 
Bay. The widest departures are the localities on the Kenee- 
naw peninsula. Probably Prof. Lawson could identity this 
beach at points still farther north. ;J; But its extension in that 
direction is not a matter of such critical possibilities as it is 
towards the south ; for the reason that the whole north side 
of lake Superior is a high coast which offers no chance for an 
outlet within the range of this beach. Tliis is not the case, 
however, towards the south. The lands bordering that side 
of lakes Huron and Michigan are exceptionally low. The 
present outlet of the upper lakes is in that direction, and 
there is the abandoned Chicago outlet, which also lacks but 
little of being active at the present time. 
JIdckinac and the East Ifichiyan Shore. Since the discov- 
ery of the Nipissing beach on the coasts of the north, a new 
significance has attached to certain beaches previously ob- 
served at other points farther south. In the first paper the 
*Not a (Ipplh of •'filty IVet upon a width of more tliaii a mile," as Mr. 
Warren Ui)ham imis il in liis letter in tlie Ameukax Geologist for 
July, 1894. From the crest of the divide down to Trout lake on the 
east there is a drop of about 2.'5 feet. IJul the shore line along the north 
side 'of the old ehannel continues level, proving- apparently that there 
was no ste(^|) tlescenl of water across tlirdivi(U\ This strongly supi)orts 
Mr. (Jilberfs suggestion as mentioned in the secoiul sentence below. 
(See introduction and first topic of the second i)ai)er.) 
fPostscript to Mr. Upham's letter. 
:j:"81<etch of the C^oastal Topography of the North Side of Lake Supe- 
rior, etc.," by A. ('. Jjawson. Twentieth An. Kept. Minnesota Geol. 
aiul Nat. fTist. Survey, 18!)ii. The bearing of Prof. I.iawson's observa- 
tions upon the place of tliis beach in the north will be briefly discussed 
in another ])aper entitle<l "The Ni|)issin!.;' Heach on the North Superior 
Shore." 
