[97] C. E. P. Brooks: The Evolution of Climate in Northwest Europe. Quart. Jour. Royal Meteorol. Soc., Vol. 47, 1921, pp. 173-194.
[98] H. F. Osborn: Men of the Old Stone Age, N. Y., 1915; J. M. Tyler: The New Stone Age in Northwestern Europe, N. Y., 1920.
[99] Encyclopædia Britannica, 11th edition: article "Ocean."
[100] C. E. P. Brooks: The Meteorological Conditions of an Ice sheet and Their Bearing on the Desiccation of the Globe; Quart. Jour. Royal Meteorol. Soc., Vol. 40, 1914, pp. 53-70.
[101] Data of Geochemistry, Fourth Ed., 1920; Bull. No. 695, U. S. Geol. Survey.
[102] Quoted by Schuchert in The Evolution of the Earth.
[103] Smithsonian Physical Tables, Sixth Revision, 1914, p. 142.
[104] Chamberlin, in a very suggestive article "On a possible reversal of oceanic circulation" (Jour. of Geol., Vol. 14, pp. 363-373, 1906), discusses the probable climatic consequences of a reversal in the direction of deep-sea circulation. It is not wholly beyond the bounds of possibility that, in the course of ages the increasing drainage of salt from the lands not only by nature but by man's activities in agriculture and drainage, may ultimately cause such a reversal by increasing the ocean's salinity until the more saline tropical portion is heavier than the cooler but fresher subpolar waters. If that should happen, Greenland, Antarctica, and the northern shores of America and Asia would be warmed by the tropical heat which had been transferred poleward beneath the surface of the ocean, without loss en route. Subpolar regions, under such a condition of reversed deep-sea circulation, might have a mild climate. Indeed, they might be among the world's most favorable regions climatically.
[105] Encyclopædia Britannica: article "Ocean."
[106] Chamberlin and Salisbury: Geology, Vol. II, pp. 1-132, 1906; and T. C. Chamberlin: The Origin of the Earth, 1916.