304 Proceedings of Metropolitan Societies. [ April, 
[These experiments of Mr. Grove probably explain the difficulty 
which working engineers have noticed of getting up steam with sur- 
face condensed water, and suggest the aeration of such water before it 
is again passed into the boiler. Mr. Grove asserts that water exposed 
to air takes it up as a sponge does water; but under some circum- 
stances it may not absorb enough to produce steady ebullition. | 
On January 29, Dr. Frankland lectured on the Glacial Epoch. As, 
however, this discourse will be treated at length in our Geological 
Chronicle, we shall content ourselves with a brief sketch of Dr. Frank- 
land’s physical theory. All our readers are acquainted with the evi- 
dences of glacier action on the surface of our earth, and the various 
hypotheses upon which the formation of glaciers has been explained. 
Dr. Frankland advanced a new theory, and conjectures that the sole 
cause of the phenomena of the glacial epoch was a higher temperature of 
the ocean, than that which obtains at present. Since the earth appears 
to be slowly cooling, it is conceivable that there was a time (not geo- 
logically distant) when the waters of the ocean existed in the atmosphere 
as aqueous vapour, as it may in Jupiter and Venus at the present day. 
After the formation of the ocean, the lecturer showed that the land must 
have cooled more rapidly than the sea. At this part of the subject, he 
alluded to some unpublished experiments of Dr. Tyndall, which prove the 
extraordinary intranscalency of aqueous vapour to rays of heat issuing 
from water. He showed also the comparative facility with which radiant 
heat passes from granite through most air. Thus we have a state of 
things tending much more to the conservation of the heat of the water, 
than to the retention of that of the land; and therefore, while the 
ocean retained a temperature considerably higher than at present, 
the mountainous regions of the earth had undergone a considerably 
greater refrigeration. ‘The evaporation from the ocean would, there- 
fore, have been greater than at present, and this increased evaporation 
must have been attended by increased precipitation, which would 
suffice to supply the higher portions of the land with that gigantic 
ice-burthen, which groaned down the mountain slopes during the 
glacial epoch. But as the oceanic temperature was higher, why was 
not the atmosphere warmer at greater elevations, and the snow-line 
raised? In answering this question, Dr. Frankland showed that the 
height of the snow-line essentially depends upon the amount of pre- 
cipitation and accumulation of snow during the cold season, and not 
upon mean temperature. The mean temperature of land under exten- 
sive surfaces of snow must have been reduced, notwithstanding that 
the amount of heat in activity on the surface of the earth was greater 
during the glacial epoch than at present. The course of events, there- 
fore, must have been as follows :—-Whilst the ocean maintained a high 
temperature, the snow-line floated above the summits of the mountains ; 
but with the reduction of the oceanic temperature it gradually de- 
scended, enveloping peak after peak, until, during the glacial epoch, it 
attained its lowest depression, whence it again rose, owing to dimi- 
nished evaporation, to its present position. 
On February 12, Dr.Wanklyn delivered a lecture “ On the Synthesis 
of Organic Bodies,” giving a brief account of the labours of Wohler, 
