is 406 ° 
of the lake Onega, the authors observed such striz exactly parallel 
to the major axis of the lake, N.N.W. and 8.S.E., evenfrom a good 
many feet under the clear fresh water, and thence rising to the height 
of twenty,feet above the summer level of the lake on the sloping 
surfaces of the rock. They then argue, that in this tract there are 
no hills of sufficient altitude on the N.N.W. to account for the de- 
termined forward direction to the S.S.E.; and as a still further rea- 
son for rejecting the application of the ‘‘ Alpine glacial theory” to 
this country, they add, that as the striz in one region have all a- 
given and. parallel direction, so must the supposed’ glacier not only 
have moved on as it were without a cause, but also have maintained 
an incredibly enormous advancing front of many hundred miles in 
length ! BiG RR 
Without pretending to offer a complete solution of so difficult a 
problem, and; after stating that many additional and even experi- 
mental researches. are required in relation'to the power of water, 
drift, and ice, they cannot avoid suggesting as a probable explana- 
tion of the chief, phenomena in the North of Russia, that currents 
strongly determined in given directions by the® elevation of the 
northern continental masses, might dislodge and set. in movement 
icefloes and detritus, which, grating upon the bottom of a sea, may 
have produced the. parallel strie. They are the more confirmed in 
this hypothesis, by the fact, that the longer axes of the lakes and 
stony ridges.of Northern Russia have generally the same direction ; 
so that the.supposed icebergs and land detritus would necessarily be 
borne in that.direction. By adopting this view, the existencé of the 
post pleiocene shells of the Vaga and the Dwina, and their relations 
to the overlying drift from the North, are in harmony; and whilst 
admitting so much of the glacial. theory as to allow, that in former 
days glaciers probably advanced. further to the South and oceupied 
many insulated tracts, and to a much greater extent than’ at the 
present.day, the, geologist, they conceive,-is alone called’ upon’ to 
define and limit.the area of Jand in Scandinavia and Lapland, oncé 
covered with:solid ice, in dog which he must of course exclude 
from such agency, the vast countries now covered by erratic blocks, 
which he ean demonstrate were deposited upon the bottom of the sea. 
Angular, block-ridges.on lake.and river Banks——On the western 
shore of the great lake of Onega, the attention of the authors was 
directed, by Colonel Armstrong*, to three parallel ridges’ of large 
angular blocks of hard grit (old red sandstone?), which occur at 
heights, varying from.:20 or-30 to 150 feet. or more above’ the level 
of the water. As these blocks were identical in ‘composition with 
the solid subjacent rock, and also quite angular, it was at once evi- 
dent that they had not been drifted, but simply rent from the solid 
rock which forms that side of the lake. On a first inspection, the 
authors were disposed to think that these appearances might have 
been caused by upheaving or vertical shocks of earthquakes, which 
they presumed might be among the last signs of the great igneous 
* Director of the Imperial Iron Foundries of Petrazowodsk, 
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