1876. ] i Proceedings of Societies. 575 
New York Acapemy or Sciences.— April 17th. Mr. George F. 
Kunz read a note on the Phosphorescence of Pectolite, as distinguishing 
it from the Zeolites. One of the members exhibited a series of Grap- 
tolites from the shales of Norman’s Kill. 
In a paper on the Causes of the Cold of the Ice Period, Dr. New- 
berry reviewed, from a geologist’s standpoint, the theories proposed to 
account for the cold of the ice period. He said these theories formed 
two categories : one, the cosmical ; the other, the terrestrial. 
In the first, the Glacial Period is attributed to astronomical causes, 
such as variation in the eccentricity of the earth’s orbit, in the angle of 
the axis of the earth with the ecliptic, or in the quantity of heat received 
from the sun, the passage of the earth through cold spaces in the 
universe, etc. The discussion of these theories he left to the astron- 
omer and mathematician. 
The terrestrial theories considered were those of Lyell and Dana, in 
which the cold of the Glacial Period is ascribed to a peculiar distribu- 
tion of land and water, the land being supposed to be high, broad, and 
continuous in the arctic regions, forming great condensers of atmospheric 
moisture, and barriers excluding the tropical currents from the arctic 
sea; and the theory of Professor Henry, which ascribes the great ex- 
tension of glaciers in the polar regions to a large amount of moisture 
thrown into the air in the tropics by volcanic agency. Both these theo- 
ties, however plausible, are based on conjecture only, and are not sup- 
‘ ported but are opposed by known facts. — 
For example, in the Tertiary Period the climate over the arctic regions 
was as mild as that of our Middle and Southern States. A luxuriant 
forest covered arctic America, — Greenland, Iceland, etc., — in which 
Were the tulip-tree, magnolias, deciduous cypress, and other plants now 
towing in the United States. At this time the land was broad, for 
re are almost no marine Tertiary deposits in the arctic regions, and 
there was land connection between America and Asia, and between 
America and Europe, forming barriers which must have excluded trop- 
l ocean currents from the polar sea. On the other hand, the land of 
“e tropical regions in Tertiary times was low, for we find marine Ter- 
tiaries bordering or covering the continents and islands. i 
ere is no evidence that the arctic lands were high and broad in the 
kce Period, but during at least a portion of this period, Greenland, En- 
gland, and Scandinavia were much lower than now. At the same time 
_. the tropical lands were apparently near their present level. 
The objections to the volcanic theory are that we have no evidence 
of unusual volcanic action in the tropics during the Quaternary age, 
and it is not certain that the production of a great amount of vapor 
there would produce glaciers in the arctic regions, as, when ascending 
to the height of a few thousand feet, the vapor would be locally precip- 
: The transfer of heat and moisture from the tropics to the poles 
88 chiefly through oceanic and not through atmospheric currents. 
