The universal geography : earth and its inhabitants

LAKES. 97to the Baltic, and no more than 76 feet above the sea, is the only member ofthe large lake system whose bed stands higher than sea-level, its greatest depthbeing GO feet. Thus it might be completely drained into Malar by deepening thejunction canal, and works have already been undertaken to reduce its level 6 or7 feet, and to regulate its outflow by means of a dam, allowing a discharge of400 cubic yards per second if necessary. Thanks to these works, thousands of acreswill be preserved from further floodings.Lake Malar itself is not yet entirely cut off from the sea. One of itsextremities is still a gulf, and when the east wind arrests the outflow, a marinecurrent, the uppsj'6, conveys a small quantity of salt water to the eastern portionof the lake. AYith its numerous channels and thirteen hundred islands, islets, orreefs, this inland sea must be regarded, not as a single sheet of water, but as anaggregate of separate basins, each at a slightly different level from the rest.In fact,it consists of four sections, disposed from west to east at successively lower levels.The Koping, or upper basin, has a mean altitude of 2 feet 5 inches above theBaltic ; the second, consisting of the "Wester&s fiords, falls to 2 feet ; the Bjorkfjard,or third, to 1 foot 6 inches ; while the Biddarfjiird, or easternmost section,at Stockholm, is about 1 foot above the Baltic.The various basins were formerlyseparated by shingly &sar, which were swept away by the pressure of the waters,thus converting the labyrinth of creeks into a united body of water. A rapidcurrent, regulated by a sluice, sets constantly from Malar to the sea under theStockholm bridges.Besides the South Swedish lacustrine basins there are in the rest of Scandinaviathirty-five lakes, each with an area of over 40 square miles, and many larger thanHjelmar itself.Such are those whence flow the chief Baltic streams—the TorneaTriisk, the Lulefi Jaur, Stor Afvan, Swedish Storsjo, and Siljan, " blue eye ofDalecarlia." But most of these remote lakes have been but partially explored,and their depth is still unknown. The Mjosen (140 square miles), however, thelargest in Norway, thanks- to its proximity to Christiania, has been carefullystudied, and found to have an extreme depth of 1,480 feet, with an altitude of397, its bed thus lying about 1,080 feet below the sea-level.In winter all the Scandinavian lakes are ice-bound for one hundred to twohundred days, according to the latitude and the severity of the season. But thestagnant waters, and even the shallow lakelets, seldom freeze to the bottom.Soonafter the formation of the first icy mantle, the heavy snows generally protect thelower waters from the frost, and thus keep the fish alive. Long fissuresare opened here and there in the frozen surface, leaving the air to penetratebelow.Like the fiords, the lakes are distinguished by their geometrical disposition.Many follow in succession along one deep trough, while others cross each other atsharp angles, grouping themselves into figures of divers forms. Thus in thesouth-west corner of Norway they enclose triangular spaces ; in Telemark they forman eccentric polygon, in which the direction of indentation is represented by avand, or lakelet of pure water. _ . • -