from the extremity of the shott El-Djerid, to form the proposed sea. In a letter from M. Roudaire to M. de Lesseps, the advantages which may be expected to result from the creation of this new sea are stated to be "an immense amelioration of the climate of Algeria and Tunis, since the moisture caused by the evaporation from the vast expanse of water will be driven by the prevailing southerly winds over these countries, forming a layer of humid atmosphere which will greatly mitigate the intensity of the solar rays and retard the cooling of the earth by radiation during the night. The proposed sea, too, being navigable for ships of the greatest draught, will also open a new commercial route for the districts lying to the south of the Aures and the Atlas range; while watercourses which from the south, west, and north converge toward the shotts, but which are now dry during the greater part of the year, will again become rivers, as they once undoubtedly were, leading ultimately to the fertilization of vast tracts of now desert land on their banks."
On the Antiquity of Man.—Starting from the opinion generally accepted among geologists, that man was on the earth at the close of the Glacial epoch. Professor B. F. Mudge adduces evidence to prove that the antiquity of man can not be less than 200,000 years. His argument, as given in the "Kansas City Review of Science," is about as follows: After the Glacial epoch geologists fix three distinct epochs, namely the Champlain, the Terrace, and the Delta, all supposed to be of nearly equal length. Now, we have in the Delta of the Mississippi a means of measuring the duration of the third of these epochs. For a distance of about two hundred miles of this delta are seen forest growths of large trees, one over the other, with interspaces of sand. There are ten of these distinct forest-growths, which have begun and ended one after the other. The trees are the bald cypress (Taxodium) of the Southern States, and some of them were over twenty-five feet in diameter. One contained over 5,700 annual rings. In some instances these huge trees have grown over the stumps of others equally large; and such instances occur in all, or nearly all, of the ten forest-beds. This gives to each forest a period of 10,000 years. Ten such periods give 100,000 years, to say nothing of the time covered by the interval between the ending of one forest and the beginning of another—an interval which in most cases was considerable. "Such evidence," writes Professor Mudge, "would be received in any court of law as sound and satisfactory. We do not see how such proof is to be discarded when applied to the antiquity of our race. There is satisfactory evidence that man lived in the Champlain epoch. But the Terrace epoch, or the greater part of it, intervenes between the Champlain and the Delta epochs, thus adding to my 100,000 years. If only as much time is given to both those epochs as to the Delta period, 200,000 years is the total result."
The Immensity of the Stars.—We take from "Le Monde de la Science" the following interesting "Considerations on the Stars," by Professor J. Vinot: "It is known that the stars are true suns, that some of them are larger than our own sun, and that around these enormous centers of heat and light revolve planets on which life certainly exists. Our sun is distant from us 38,000,000 leagues, but these stars are distant at least 500,000 times as far—a distance that in fact is incommensurable and unimaginable for us. Viewed with the unaided eye the stars and the planets look alike, that is, appear to have the same diameter. But, viewed through the telescope, while the planets are seen to possess clearly appreciable diameters, the stars are still only mere luminous points. The most powerful of existing telescopes, that of Melbourne, which magnifies 8,000 times, gives us an image of one of our planets possessing an apparent diameter of several degrees. Jupiter, for instance, which, seen with the naked eye, appears as a star of the first magnitude, with a diameter of 45″ at the most, will in this telescope have its diameter multiplied 8,000 times, and will be seen as if it occupied in the heavens an angle of 100°. Meanwhile a star alongside of Jupiter, and which to the eye is as bright as that planet, will still be a simple dimensionless point. Nevertheless that star is thousands of times more voluminous than the planet! Divide the distance between us and a planet by 8,000,
