2 ioe eo} Erratic Phenomena about Lake Sauer | 87 
aS ern “Asia; hich has not yet been studied in this respect; that is’ 
_. tosay, at the same time, over a space embracing two hundred 
' degrees of longitude. 
Again, the action of this cause must have been such, and I 
insist strongly upon this as a fundamental point, the momentum 
with which it acted must have been such, that after being set in 
otic on in the north, with a power sufficient to carry the large 
boulders which are found everywhere over this vast extent of, 
st 
_ land, it vanished or was stopped after reaching the thirty-fifth 
_: “degree of northern latitude. 
Now it is my spe —— that natural philosophy — 
: -mathematics may settle the question, whether a body of w 
of sufficient extent to a such phenomena can be set ga mo-" 
tion with sufficient velocity to move all these boulders, and nev~ + — 
ertheless stop before having io over the whole surface of the 
institute a comparison, it will be seen that there is nowhere a” 
current running from the poles towards the lower latitudes, either 
in the northern or southern hemisphere, covering a space equal to 
one-tenth of the currents which should have existed to carry t the 
etratics into their present position. ‘The widest current is west 
of the Pacific, which runs parallel to the aries across the 
of which is scarcely fifty degrees. This aa as a matter of 
— establishes a regular rotation between the waters flowing” 
and carrying floods of water in that direction, is maintained 
even when ae extend over hundreds of degrees of latitude, as 
the Gulf Stream does in its oe sidmoens are deflected where 
they cannot follow a straight cou 
ow without appealing a more detail to the mechanical 
conditions involved in this inquiry, I ask every unprejudiced mind 
acquainted with the distribution of the northern boulders, whether 
there was any geographical limitation to the supposed northern 
culrent to cause it to Jeave the northern erratics of Europe in 
. 
