Some day the incredibly small but progressive changes taking place on the earth will produce a condition of things which will render human life impossible, but how and when are matters on which scientists are far from being agreed. The latest theory, laid before the recent conference of the British Association -by Professor Flinders Petrie, is that the end will come in about 200,000! years, by reason of the disappearance from the atmosphere of the Jast traces of carbonic acid gas, which, though forming only 0.029 per cent. of the atmosphere, plays an important part in the operations of nature.
But if M. Martel, the well-known French scientist, is right, we need not worry about the nature of the atmosphere 200,000 years from now, for his investigations into the erosion and corrosion of the earth's surface have led him to predict the end of the human race in a few generations. The water level of -the globe," M. Martel tells us, "is being continually lowered, and un-we can discover how the human race from lack of water in centuries." On the other hand, Sir Archibald Geikie has predicted the end by too much water. "A universal decay of the land is going' on at such a rate," he said a few years ago, "that a comparatively short period will suffice to reduce most of the dry land to the level of the sea. and bring about a second deluge."
Where geologists are concerned, a "comparatively short period" may mean a hundred thousand years, or even a million years, for they have always protested against the miserably inadequate period of 400,000) years which, until the discovery of) radium upset all previous _calculations, was the utmost physicists: conceded as the age of the earth. The second deluge is, therefore, probably more remote' than Pro: fessor Petrie's epoch of a carbonic acid gas famine. But M. Martel's water famine is very near us. Great-great-grandchildren of some young Qeilnvolved in" the" stupendous ple now living may conceivably
struggle to conserve the failing water supply of the globe foreseen by him—a struggle which Professor Lowell has assured us is now going on in the planet Mars.
It is thus unsettling to know that recent report to the South Africa Parliament called attention to the; fact that many parts of the Union are becoming uninhabitable by re-son of the gradual disappearance of the water supplies. And a few years ago a Herr Walser announced that Europe was drying up.
Other scientists have foreseen the end of the human race by intense cold, the result of another glacial epoch. But Antarctic exploration has proved that the southern ice-cap is shrinking, and opening up a new habitable region, and pointing to the time when cereals will be
Text read from the printed page and cleaned; old type leaves the occasional error.