Spitaler, R. “Das Klima des Eiszeitalters.” Prag, 1921. Lithographed. [Eccentricity of earth’s orbit. Reviewed in the _Meteorological Magazine_, London, September, 1921.] Simroth, H. “Die Pendulationstheorie.” Leipzig, 1908. Kreichgauer, P. “Die Aequatorfrage in der Geologie.” Steyr, 1902. Wegener, A. “Die Entstehung der Continente und Ozeane.” _Die Wissenschaft_, Bd. 66, Braunschweig, 1920. Köppen, W. “Ueber Aenderungen der geographischen Breiten und des Klimas in geologischer Zeit.” Stockholm, _Geografiska Annaler_, 2, 1920, pp. 285-99. Brooks, C. E. P. “Continentality and temperature.” _Quarterly Journal of Royal Meteorological Society_, Vol. 43, 1917, p. 169; and 44, 1918, p. 253. [Influence of land and sea distribution.] Enquist, F. “Eine Theorie über die Ursache der Eiszeit und die geographischen Konsequenzen derselbe.” _Bull. Geol. Inst._, Upsala, 13, 1915, No. 2. [Influence of land and sea distribution.] Hobbs, W. H. “Characteristics of existing glaciers.” New York, 1911. [Glacial anticyclone.] TABLE OF GEOLOGICAL FORMATIONS { Recent QUATERNARY { Pleistocene { Pliocene TERTIARY or { Miocene CAINOZOIC { Oligocene { Eocene { Cretaceous MESOZOIC or { Jurassic SECONDARY { Triassic { Permian { Carboniferous { Devonian PALÆOZOIC { Silurian { Ordovician { Cambrian PROTEROZOIC Pre-Cambrian CHAPTER II THE CLIMATIC RECORD AS A WHOLE It is a remarkable fact that one of the oldest known sedimentary rocks is glacial in origin, and indicated the presence of an ice-sheet at a very early stage in the earth’s history. This is a “tillite,” or boulder-clay, discovered by Prof. Coleman at the base of the Lower Huronian (Early Proterozoic) of Canada. It extends in an east and west direction for 1000 miles across northern Ontario, and northward from the northern shore of Lake Huron for 750 miles. It rests on a scratched or polished surface of various rocks, and the included boulders are not always local, but some have been brought from a considerable distance. All these characters point to a large ice-sheet. Traces of Proterozoic glaciations have been discovered in various other parts of the world, and some of these may be of the same age as the Canadian ice-sheet, but they cannot yet be dated exactly. An interesting example is western Scotland, which J. Geikie considered to have been glaciated by ice from the north-west which has since sunk into the North Atlantic. Other glacial remains have no doubt been destroyed or deeply buried, while some may still await discovery, and at present we must be content to note the occurrence of a glacial period at this time without attempting any description of the distribution of climates over the globe.