Part 9

Except hydrogen.

Moreover, in cooling the subjection of one pole to glacial and the other to temperate or sub-tropical conditions, as argued by Dr. Croll, would have subjected our planet to very peculiar “cooling strains,” as they are termed by foundrymen. Whereas the slow and uniform cooling, as herein described, is productive of maximum thickness, strength and uniformity of crust; and, as will be explained later, this crust was finally shrunk in upon the interior mass by being subjected to the maximum degree of cold to which it can be exposed during the existence of the sun as a source of heat.

The prime objection which is urged against all previous theories is their inadequacy. We here have a perfectly adequate cause--resident earth heat to supply evaporation and shut out solar energy, which energy can only act the part of a conservator of the glacial conditions until the exhaustion of earth heat, when its power can be spent in melting glacial ice, and in gradually establishing the present conditions.

It will again be noted that the isotherms inside of 32° - y° Far. were maintained by earth heat, and therefore independent of equatorial or polar exposure to solar heat. Consequently their intersections were upon different lines from those isotherms exterior to 32° - y° Far., which latter were mainly dependent upon solar heat. It will also be observed that solar heat, when it reaches the lower, denser regions of the atmosphere, is trapped and therefore capable of establishing and maintaining higher temperatures than in the upper atmosphere.

The truth of this fact is easily established by either observation or experiment. At the close of a hot day should a slight cloudiness supervene, the loss of heat by radiation from the surface is checked; the air at the surface, and the surface, remain at the same temperature, and nature’s delicate differential thermometer--the deposition or non-deposition of dew--records the non-transcalency of clouds, in terms worthy of consideration.

Again, let two delicate thermometers be exposed, one to the air temperature and the other in addition to direct solar rays; the latter will mark the increased temperature due to such exposure. Upon the intervention of a cloud, or even a jet of steam, both instruments will mark the same temperature.

See Physical Geography of the Sea. Maury, 6th ed., p. 212, et seq. Climate and Time, Croll, p. 60, et seq. Climate and Cosmology, Croll, p. 51.

Astronomers agree that there must exist upon Jupiter a high degree of heat, and yet no refinement of thermometric determinations can detect any more heat from the Jovian surface than should be reflected from the sun.--See Young’s General Astronomy, page 353; also History of Astronomy During the Nineteenth Century. Clerke, pp. 335-338.

The author is aware that this statement is at variance with the opinion of many Geologists of high repute, as may be seen from the following quotations: “It is evident that the idea of connecting the phenomena of the internal heat of the globe with terrestrial climates, whether of the present or of past geological ages, must be entirely abandoned, as it has been, by most writers on this subject. The hypothesis cannot be allowed to stand as even one of the possible theories of climatic change.”--The Climatic Changes of later Geological Times. Whitney, p. 261.

“The first theory brought forward to account for glaciation was that the earth, having been originally in a fiery state, had in cooling passed from a condition of universal warmth to a more and more frigid state, until the present conditions were attained. This is the least tenable of all theories, for it neglected the now evident fact that there had been changes from cold to warmth and back again to cold. However, as it was invented before the existence of glacial periods was suspected, it long commanded a general assent, and was the opinion that held the ground until near the middle of this century.”--Glaciers. Shaler & Davis, p. 70.

The physicists who have held that earth heat was a cause of the Ice Age are Prof. E. Frankland, F. R. S., Prof. A. Woeikof and Startorius von Walterhausen. Not one of the three, however, seems to have had a clear conception of all the facts and conditions although their views were in the main sound.

The author hopes to extend the views held by these writers and to show that the whole range of climates as recorded by fossil and existing life is capable of correct interpretation, in accordance with known laws, and without the intervention of suppositions and assumptions. And moreover, to base his deductions upon a general plan applicable to any planet and capable of explaining conditions prevalent upon other planets, notably upon Jupiter and Mars.

To those interested in a verification of this very wide distribution of glaciation, the following short list of authorities is recommended:

Asia.--The Great Ice Age (Giekie); Note on the Glaciation of parts of the Valleys of Jhelan and Scind Rivers, in the Himalaya Mountains of Kashmere, Lat. 34° N. (Capt. A. W. Sleff), F. G. S.; Jour. Geol. Soc., London, vol. xlvi, p. 66; Mem. Geol. Survey of India, vol. xxii, also vol. xiv; Record Geol. Survey of India, Nov., 1880; Jour. Asiatic Society, Bengal, xxxvi, p. 113; Brit. Association Report, 1880; Text Book of Geology, A. Giekie, LL. D., etc., p. 911.

Europe.--The European Glacial Literature is too extensive to mention.

America.--The Ice Age in North America (Wright); U. S. Geological Reports; State Geological Reports of Ohio, Kentucky, Pennsylvania, New York, Minnesota, Nebraska, Colorado, Illinois, etc.; Virginia, Am. Jour. Sci., vol. vi, p. 371; California, Am. Jour. Sci., vol. iii, p. 325, vol. x, p. 26.

South America.--Geological Sketches, Agassiz, p. 154, et seq.; Geol. and Physical Geog. of Brazil (Prof. Ch. Fred. Hartt), pp. 22, 28-9, 469-70, 490, 558.

Africa.--Geol. of South Africa (Stow); Quart. Journ. Geol. Soc., London, vols. xvii and xviii.

Australia and New Zealand.--Climate and Time (Croll), p. 295; Am. Jour. Sci., vol. 32, third series, p. 224; Proc. Linnæan Soc., N. S. W., May, 1886; Prestwich’s Geol., vol. ii, p. 467; Rep. Brit. Assn., 1881, p. 742.

“The shrunken or vanished ice of mountain ranges is indeed equally characteristic of the Himalaya, the Lebanon, the Alps, the Scandinavian chain, the great chains of North and South America, and of other minor ranges and clusters of mountains.”--Ramsay, Quart. Jour. Geol. Soc., 1862, p. 204.

Many geologists are misled by the greater modification of tropical drift by sub-aerial agencies. Having been longer exposed to such agencies, greater modifications are to be expected. The apparent improbability of tropical glaciation seems to deter many scientists from believing that such glaciation could ever have occurred, yet the same scientists will accept the fact that fossil life establishes the existence of tropical or even torrid conditions within the polar circles during past ages.

See Geological Sketches, Agassiz, p. 154, et seq. Also Physical Geography and Geology of Brazil, Prof. Ch. Fred. Hartt, pp. 22, 28, 29, 217, 469, 470.

See the author’s views in Physical and Geological Traces of Permanent Cyclone Belts. Trans. Technical Society of the Pacific Coast, Vol. VIII, No. 1, June, 1891.

Phil. Mag. (4), Vol. XXV, pp. 1-14. Trans. Royal Soc. Edin., Vol. XXIII. Influence of the Earth’s Secular Heat upon Climates. Hopkins, Jour. Geol. Soc., Vol. VIII.

Climate and Time, Climate and Cosmology.

The Cause of an Ice Age, chapters 5 and 6.

Nature, May 1891; S. E. Bishop.

Circulation of the Atmosphere of Planets.--Trans. Technical Soc. of the Pac. Coast, Vol. IX, No. 5; pp. 136-143.