Page 18 Advertisements Column 3

Otago Daily Times, Issue 18802, 3 March 1923, Page 18

—Greenflies reproduce very rapidly, 19 generations being possible in 16 weeks. That the continents of the earth are not fixed, but adrift, ra the startling theory propounded by Dr Wegener, a German geologist. According to this theory the land masses that eventual!}* become welded together into continents were originally dependent from the North and South Poles like bunches of grapes on their stalks. Thence they broke away, eventually coming to anchor near where they are at present. But just as no ship can be anchored immovably for all time to a shifting bottom, so is it with continents. They tend to drag their anchors, as it were, and the motion is away from the Poles and from cast 10 west. This drifting motion, however, is not uniform. America, say these theorists is going west faster than Europe. Greenland is travelling even faster in the same direction, observations taken in 1670 and ISO 7 showing a drift of about three-quarters of a mile in the intervening period. Dr Wegener’s explanation of these movements is a curious one. Continents are composed of comparatively light rocks, known collectively to geologists as “sial,” and the rocks below the sea, termed “sima,” are far heavier. The ama extends under the sial of the continents, which float upon its heavier surface and are upborne by it like icebergs in an ocean.