WHERE THE TIDE COMES FROM

Evening Star, Issue 19064, 6 October 1925, Page 8

WHERE THE TIDE COMES FROM

“ Much mystery still envelops the actual process of the birth of the tides. This much we do know: every twelve hours and a few minutes, out in the vastly wastes of mid-Atlantic, a gigantic ‘tide wive’ is born,” says a writer in the ‘ Daily Chronicle.’ Strange* as the fact sounds, this wave travels at the rate of hundreds of miles an hour. Its very speed, however, makes it of imperceptible height, for it is more than 1,000 miles wide from front to back. “It hits what geographers call the Continental shelf ’ (the outlying shallows of Europe, on which tho British Isles are perched) from the direction of about AV.S.W. The shallow waters abruptly slow it up to a mere ninety miles an hour, simultaneously steepening the wave. “The racing Atlantic tide wave first hits the west coast of Ireland, on which it splits, then sweeping around the mainland of Britain by the channel between the Orkneys and Scotland to the north, and by tho English Channel to the south. It reaches Liverpool (behind Ireland), the northernmost tip of Scotland, and Dover about simultaneously. •• Once round Thurso- the onracmg tide, steadily losing momentum, reaches the Thames Estuary some twelve hours later. Its journey down the North Sea is a leisurely fifty-mile-an-hour trip. There is a most curious ‘ dead-water area ’ out in the North Sea halfway between Holland and England where the tide thrusts from nortfi and south happen to neutralise each other, and no tide occurs in consequence. „ ~, “ The biggest range or tides m Europe—and even, 1 believe, in the world—are those in the Channel Isles and along the Breton coast between Granville” and Brest, where the big main thrusts of tho Atlantic tidal wave piles into the comparatively narrow neck of the Channel.”