POPULAR MISCELLANY. 



285 



we may imagine our river straight, evenly 

 broad and deep, with no marked channel, 

 and without tributaries. The formation 

 of a channel begins as soon as a bit of 

 the earthy constituents contained in the 

 water is deposited on the ground under it. 

 This causes an unequal distribution of 

 the weight of the water, and a stronger 

 inclination toward one or the other edge. 

 The deposit slowly grows, and a sand-bar 

 is formed, which presses the current over 

 toward one side and gives it an angular 

 direction. This causes it to strike with 

 more force against one of the shores, and 

 to wash it, eat it away, or undermine it, 

 equally whether it be of earth or stone. 

 Should there be a tributary coming in from 

 the opposite side of the sand-bar, that will 

 occasion the formation of a second bar, and 

 this will cause the current to make another 

 turn and render its course serpentine. In 

 this way a system of bars is formed, that 

 are represented in the course of time by 

 dry alluvial deposits, from which the river 

 has been constantly pushed to one side. 

 Many of the peculiarities of African and 

 other rivers may be explained by reference 

 to these principles. The great bends of the 

 Congo and the Niger may be accounted for by 

 supposing that the hills that run parallel to 

 their courses were weathered most on the 

 side most exposed to the sun so as to cause 

 a constant growth of the bars on the north 

 side and a gradual pushing of the stream 

 toward the equator. In Hungary, the courses 

 of the streams are modified by the opera- 

 tion of another force, that of the equinoc- 

 tial winds called the koschava^ which blow 

 in the spring and fall for days at a time 

 from the southeast. The waves are driven 

 by the wind, especially at the time of high 

 water in the spring, with more force against 

 the western bank, and make longitudinal 

 excavations in it at the level of the water. 

 After the retiring of the flood, the over- 

 hanging bank gives way and slides into the 

 river, with a noise which is quite familiar to 

 the people, and well understood by them. 

 These excavations, extended and deepened 

 by subsequent operations of the same kind, 

 result in the formation of large bends ; and 

 the river has become very serpentine, with 

 numerous narrow peninsulas jutting out at 

 right angles to its current. Finally, the 



peninsulas are cut through and formed 

 into islands, to become in time, as has been 

 the case in some instances, by the opera- 

 tion of continued changes of the stream, 

 a part of the other bank. Observations of 

 this kind have been made in the Danube, 

 and the phenomena accounted for by them 

 are familiar on other rivers. Changes by 

 another kind of process are caused by the 

 fall equinoctial winds, which, instead of 

 finding high water in their way, take up 

 the^ dry sand and deposit it in drifts where 

 they vrill exercise a modifying influence on 

 the course of the river. The changes that 

 have taken place in the Amou-Darya of 

 Turkistan, under which its course has been 

 diverted from the Caspian Sea to the Sea 

 of Aral, are probably effects of an agency 

 of this kind. 



Russian Scientific Societies. — Science is 

 promoted in Russia by several societies 

 that are very active in their respective 

 fields of investigations, and which have 

 earned for their country a respectable place 

 among the nations where knowledge is dili- 

 gently and intelligently cultivated. The 

 Kiev Society of Naturalists was formed in 

 1869, and is supported by a considerable 

 membership. Its chief aim has been the ex- 

 ploration of the natural history of the neigh- 

 boring provinces. Its published "Trans- 

 actions " bear evidence of good work done 

 in geology, zoology, botany, and kindred 

 sciences. Since 1873 it has undertaken the 

 yearly publication of a systematic catalogue 

 of papers in mathematics, pure and applied, 

 natural science, and medicine, printed in the 

 numerous scientific publications of the em- 

 pire. The East Siberian branch of the Rus- 

 sian Geographical Society, having already 

 contributed largely to the purely geographi- 

 cal exploration of the unknown parts of Si- 

 beria and the adjacent countries, has now 

 become engaged upon a more thorough sci- 

 entific exploration of Siberia itself. Among 

 its later publications is an excellent geo- 

 logical map of the coasts of Lake Baikal. 

 The Siberian branch of the Geographical 

 Society has within the last few years taken 

 a lively interest in anthropology and archae- 

 ology, and has been the means of making 

 known many valuable discoveries in these 

 branches. It has also paid much attention 



