Page:Encyclopædia Britannica, Ninth Edition, v. 14.djvu/234

222 that the s of several wet s would have to accumulate before forcing a passage. The result would be a of a period corresponding to the recurrence of series of wet or dry s. Were the lake situated at or near the level of the, its ial position would give it such a preponderance of  over the whole  as to keep its outlet constantly open; but its actual position, 2700  above the , produces an alteration in , equivalent to an increase of , which would place it in the trade  region rather than in that of ial calms and s. That such is actually the effect is shown by the range of , which is moderate (59 to 83 ),and the fall(27 to 30 ), which is almost exactly that of. The lakes, from their immense size and from their ial position, possess a peculiar interest for the physical, and it is to be hoped that before long we shall have sufficient s to give a general idea of the size of their basins, and also  observations to show the effect of a vertical  on large bodies of  at a moderate , and removed from the disturbing influence of ic. As might be expected, in lakes which have no overflow, the ly rise and fall is often considerable. In the Great Salt Lake in Utah, the greatest depth of which is 56, changes of level are accompanied by great changes in surface, and also in ness of. In the y the  stands 10 or 12  higher than in the dry. The following table shows the composition of the s of various  lakes, that of the - in the  being added for comparison:—

 

 

 

 This table embraces examples of several types of lake. In the,, and open s we have examples of the moderately, non-saturated s. In the , a branch of the , the , and the  we have examples of saturated s containing principally s. The  is an example of the  s which also occur in , , and other. Their peculiarity consists in the quantity of dissolved in their s, which is collected by the inhabitants for domestic and for  purposes. The reader will be struck by the quantity of  dissolved in  which contains so much. The analysis in the table is by Abich, quoted by Schmidt in his interesting “Études Hydrologiques,” published in the Bulletin de l’Académie de St Petersbourg. Another analysis by De Chancourt, quoted by Bischof, omits all mention of, but inserts the. The limits of this article do not admit of the discussion of the many interesting phenomena connected with lakes. With regard, however, to a former connexion of the with the, which has been so often suggested, it seems improbable, both on and on  grounds, that they were ever connected as s, that is, in the same way as the  is connected with the ; but, if we consider the  of the  district, we see that the lowest summit level of the  between the two s is in the, 86  above the. Were the of the  to change only very slightly for the moister, its s might easily rise the 196  which would enable it to overflow towards the, while a relapse towards dryness would be followed by the retreat of the s, which would be then confined as they are now to the basin of the. It is important, therefore, to bear in mind that no dislocations are required to produce enormous changes in the level of  lakes; we require only changes of, and these very slight. There can be little doubt that, if the climate of the extended across the  to the, the latter would now stand 200  higher, would be , and would overflow into the. For other aspects of the subject see. (J. Y. B.)   DWELLINGS, as their name implies, are, not on the dry , but within the margins of  or  at some distance from the shore. The of the  in the  are described by Goering as composed of  with low sloping roofs perched on lofty piles and connected with each other by  of planks. Each consisted of two ; the floor was formed of split stems of  set close together and covered with ; they were reached from the shore by dug-out s poled over the shallow s; a notched  trunk served as a  and the piles were so firmly driven that no shakiness was perceptible even when the  were crowded with. In such a the advantages of dwelling in  so situated are obvious. The custom is common both in the and in the  of the  and ; indeed the name of the province of  was given to it from the prevalence of these pile-dwellings along its shores. A similar system prevails in. D’Urville describes four such in the, containing from eight to fifteen blocks or clusters of , each block separately built on piles, and consisting of a row of distinct  accommodating a number of. Cameron describes three thus built on piles in  in, the motive here being to prevent surprise by bands of -catchers. Similar s have been described by travellers, among the of, in , in the , on the  of , and in other places. have referred to the former existence of the custom in and. Hippocrates, writing in the, says of the people of the  that their  is hot and marshy and subject to frequent , and that they live in  of  and   in the midst of the s, and use  of a single  trunk. Herodotus, writing also in the, describes the  of  as living in  constructed on platforms supported on piles in the middle of the , which are approached from the  by a single narrow 