124 The American Oeologist. Feb. ism 
soutliern states, where a climate both humid and warm acts more effi- 
ciently, as pointed out by Kussell, to extend this change to consider- 
able depths. 
Professor Shaler affirmed his belief that no lowering of the mean 
temperature is needed to cause the beginning of ice accumulations, 
which he thinks would result from increase in the evap<iration of mois- 
ture from the ocean and its transfer by storms spreading over the land. 
In any attempt to describe the glacial climate, account should be taken 
of the fact that the ice^sheet advanced, api)arently by a forced march, 
to latitudes far south of the normal snow-plane. Tliough the ice push- 
ed across the Ohio river at Cincinnati, no trace of local glaciers can be 
found on the mountains of North Carolina only about two- hundred 
miles distant to the south ; yet they rise more than 5,000 feet higher, 
and would be mainly above the plane of perpetual show, i)rovidecTthis 
was represented by the ice-sheet. The final melting of the ice was 
greatly accelerated, according to professor Shaler, by depression of the 
land below its present level and the breaking up of the ice-sheet into 
bergs. 
He regards the great conglomerate formations of earlier geologic 
eras, notably the Carboniferous and Permian, as drift deposits, prov- 
ing the general prevalence in so remote times of climatic conditions 
favoring glaciation. To this Mr. Bouve objected, ascribing the origin 
of conglomerates to wave action on seashores and cliffs, often working 
over rock material Avhich had become separated as boulders by subae- 
rial disintegration. 
Professor Davis considered the action of the great cyclonic storms, 
producing snow in the upper cloud strata, which in failing beneath the 
thermal jjlane of 32° Fahrenheit becomes rain. He thinks that to start 
a glacial epoch refrigeration of the portion of the year when the pre- 
cipitation now is rain would be necessary, keeping it generally during 
more months in the form of snow until it reaches the ground. Dr. 
Croll's theory seems inadequate to account for such climatic changes, 
and the restriction of large glaciated areas to the parts of the globe 
adjacent to the North Atlantic ocean suggests that the causes of ice 
accumulation were terrestrial instead of cosmic. But no satisfactory 
explanation of the origin of the glacial climate is yet found. Serious 
objections appear against the view recently urged by Upham with 
some modification from the opinions long before advanced by Lyell 
and Dana, that the glaciated areas became covered by snow and ice 
because of their being greatly uplifted for a geological short time as 
continental plateaus, giving cool climate throughout the year; and the 
suggestion of Chamberlin that the position of the earth's axis may 
have so changed as to bring these areas within the Arctic circle, is per- 
haps not less difficult for oar acceptance. 
Mr. a. S. Tiffany, of DAVENroRT, Iowa, sends the fol- 
lowing RECORD of a deep well recently drilled at Dixon, Illi- 
nois. The well has a flow of 400 gallons of water per minute. 
Drift, 150 feet ; Yellow magnesian limestone, 40 feet; White 
sandstone, 410 feet ; Red argillaceous shale, 50 feet ; Red aren- 
aceous shale, 25 feet ; Ash colored shale, 225 feet ; White sand- 
stone, 135 feet; Drab colored magnesian limestone, 165 feet ; 
Dark grav sand, 100 feet; Light gray sand, 150 feet; White 
sand, 300 feet. Total depth , 1750 feet. 
According to Prof. J. E. Todd a deep well is being bored at 
Le Mars, Iowa, in pursuit of oil. The record of the boring has 
been neglected, the operators having no faith in "geological 
theories," but full confidence in the "dictum of the drill." 
