118 Scientific Intelligence. 
So that in = Sun case the earth receives about one-tenth less heat 
than in the o ; 
n’s aia um distance occurs at present a _ after nr i 
midsummer of the northern hemisphere. hen it occurred at : 
same time of the year during the period of eaater “ecentity, 
the earth at our midsummer was receiving only nine-tenths 
quantity of heat which it now receives at that time of the year. I 
cannot calculate the effect on climate; but it must have been very 
great, not only directly, by depressing the snow-line, but as Forbes 
remarks in the place cited above, indirectly by chilling the air—and 
I will add, by filling the North Sea with the iceber ¢@s which must 
have broken off from the glaciers that filled the Norwegian fiords, 
s they do now from the glaciers of Greenland. We have plenty 
of evidence of iceberg action during the glacial perio 
I believe I have shown that glaciation ‘depends s chiefly on a cold 
summer, but part ies on .an abundant snow-fall, I have now : 
to. show that a sae of cold summers, caused as I have explained, 
must As also one of age! Ge winters ; so ~~ the two conditions 
favorable to glaciation will oceur toget 
ring the mild winter of the a hemisphere, there is a 
nt 
hot summer in the opposite one. Increase of temperature promotes 
increase of evaporation in a much greater ratio than that of the 
increase of temperature ; and increased evaporation in the summer 
hemisphere will produce senrenad snow-fall in the winter one. 
tale + oe ; : 
now t prese 
to a great extent precipitated in the other; for, were it not so, the 
seathern owe ere, by reason of its greater extent of ocean sur- 
on my ae was in othe winter of the glaciated hemisphere), must 
be more active than ever it is now; adh when the earth, at ‘either 
solstice, was nearer th n than is ever the case now, 
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8 eres, which would involve the Sepomtion as rain or snow i2 
e winter hemisphere of a great part of the moisture evaporated 
in the oe on 
r continues with remarks on fiords as results of the 
yj ec 
Se a ee SS ee 
ivers ; by Dr. F. V. Haypern, Assistant under the 
direction of Captain (now Lieut. Col. and Brevet Brig. Gen. 
. F. Reynoips, Corps of Engineers, 1859-60, with a colored 
—Several 
with much interest. The — 
