FACTS ABOUT LAKES.

Oamaru Mail, Volume XXXVI, Issue 10060, 30 January 1909, Page 3 (Supplement)

FACTS ABOUT LAKES.

(By Dr Andrew Wilson.)

The enjoyment of scenery is greatly enhanced by a little knowledge of the causes and actions which have led to tlie special conformation of the land features we see and. admire. People lose an immense amount of the pleasure to be obtained from foreign travel through their neglect to' make themselves acquainted with the outlines of the history of any region they visit. Imagine the intellectual benefits wlzioh may accrue from a visit to Switzerland, if the tourist has been, 'led to take a- prior interest in the story of glaciers, or the biography of mountain-ranges. A landscape and its features would then interest him in the sense in which a "visit to a cathedral interests.the person who is acquainted with architectural details and with the history of the venerable pile. Your casual tourist who sees scenery but understands it not-, does not possess even the doubtful advantage of the verger s droning and mechanical description of the .church under his care. Lord Avebury s books 011 scenery in relation to the forces which have, sculptured and, produced it, might' well ..lie circulated and read with jirofit by thousands -of educated people who would thus enjoy a trip abroad to an extent they do, not even dream of as things' are. ....

It is not necessary to depart abroad, however, to find many phases of naturestudy such, as throw a new 'light- upon the world's history. The laud we live in is full of excellent -examples of scenery, such as form valuable and interesting objectlessons in the lore of our world. In truth, within, the confines of Britain we have a variety of scenery such as few other countries possess and exhibit. We have mountain and valley, plain and upland, river and lake and the sea, all presenting the abundant "harvest of a quiet, eye" to the man who can construe the language in which nature speaks of the past, history of the world. Among the typical features of Britain and the world at large, lakes fall to be considered.- Just, as an island is much .more than "a piece Of land surrounded by water," when its history is written, and when different islands are seen to have been differently evolved, sr> .there are lakes and lakes, and the story of.one sheet of water varies widely from that, presented to- the geologist's , eve by 'the history and origin of, it may be, a neighbor water-surface. The child at school will tell us of lakedistribution of typical land. He will remind us of the lakes of of England and South of Ireland. There is the great chain which constitutes the Caledonian Canal, with deep Loch 2\ess as the •typical basin. Then we find Swiss and Italian lakes familiar to many of, us, and the Jvorth American lakes,, which are inland seas for extent, and lakes in Asia and Africa form prominent features of the maps. Apart from tlie fact that, man has a deep interest an many lakes by reason of their affording him means of watercommunicatdon, the fertility of a district may, to a. very large extent, be dependent on the storage of water-supply a lake represents. Possibly the first glance at. lakehistory which, may afford - adequate food for thought -is that which refers to ancient lake-basins. The .geologist points, out .to us that most lakes tend to be filled up—"siilted up," is liis expression—by the materials brought down by. the rivers which enter them. The Rhone enters the Geneva Lake muddy and full of sediment, which the lake, bed receives, and leaves' it as clear as orysta.l. Around every .lake alniost, there is flat land, siveet meadows and pastures.green, .which really represent, what once formed. part of the l'alie-basin. Through such . land often meanders , tlie stream that represents the. river,. whose sediment'converted, lake into land. Thun and 1 Brienz, in Switzerland, were once one lake, but the. intervening land; was forriied by the siltirig-up of, the intervening tract, and Interlaken.to : day stand's on this relatively newly-fprmed land. liake basins.may .become thfemselyes dry land; You, can.this, in the. case, of the.: Engelberg-.. Valley- in Switzerland, as I have 6aid, .and, equally, and on a larger scale, in the "terraces", of...Lake Bonneville, the dry . basin . whereof. the . Great Salt. Lake, represents the - watery remnant. Our:lakes may .lie,in natural-land .hollows which resulted froni.-volcanic But other lakes . are certainly - the .craters of eitinct-volcanoes. - 'Those, of Italy- are of this, character—many of . them, at least—and the Crater, Lake of..Oregon is a .very typica.l example of a lake of, this -kind. Water occupies the place, of the.lire and hsait/of ancient days. : Again, movements of, .'land, raising the land level, and thus placing a barrier between the sea«and a frith or arm.; of the ocean, converts .the frith,; or fiord," into ,-a lake. The,-lakes are thus, land-locked. sea waters. Such was the origin ,of ..CarnO. and- Maggpore, .-and the Caspian,. Sea , and , Arfil■; Lake- : a-re also .to be,ranked-with such.sheets of water. -.. The. proof, of-,- this origin is 5 that we, find . in the living animals of such; lakes .evidences of. the ancient,,forms pr,qper,-to..the sea. " But/ in our : . own .land . especially, many lakes, owe .their, existence, tp another, kind of cosmicaili /aetion."Tjhie Great Ice Age has feft , its, imprint on, the whole 0f... the North., of ,-Europe. . Tlie. great-ice sheets,' or, glaciers, as: they ploughed J their way ovec, the.land, ; surfaee, scooped out the earth, and thus ;gave opportunity, for .lakeorigin. In sthe- typical ~glacier regions 'lakes abound, ,-and. ! .tu# evidences of demonstrating ,the. .manner-in which great world hollows were, excavated. Tie ;very,Act-,thatjsalt.lakes exist^ tp'-da.y is in itself -an evidence of that - .origin-: of Jakes which:- is .to be ascribed .to ;]an<l • movements lifting-. up the; ocean margin and: damming, back ,the water: of. a-.-fiordV The original salt-is not ;lostiby ; evaporation, i-aaid- so .these.:salt;lakes,: many'.of them, .are condensed-and a:re salter. than the. sea itself. Therefore, of lakes, as of other,; scenic-features,' we may ask with Kinsley, "How; did tthis lake come here;?-''