NATURAL PHILOSOPHY. 83 



their right banks perceptibly more than their left ; and this opinion 

 seems to have found currency among the French academicians, when- 

 ever the subject has been discussed at the meeting of the Institute. 



Regarding this question as one of fact rather than of opinion, M. 

 Von Baer, in an elaborate memoir, read before the Imperial Academy 

 of St. Petersburg, and lately published in the bulletins of that body, 

 has brought together so large a mass of instances, drawn from observa- 

 tion of the courses of almost all the rivers of any note, both in Euro- 

 pean and Asiatic Russia as to justify this enumeration as a general feature 

 (not of course, without local exceptions, owing to the natural inequalities 

 of ground), over the whole of that vast region, that the right bank of a 

 river is higher and steeper ; the left the flatter and more alluvial one, 

 and more subject to inundation, the law being so general, that over 

 vast tracts of country, it may be predicted, almost without risk of fail- 

 ure, from the aspect of a stream in this respect, in which direction it 

 runs. It deserves remark, that this general tendency has already been 

 noticed by more than one geologist of eminence, without any suspicion ^ 

 of its cause. Thus, even so long ago as 1847, Major Waugenheim von 

 Qualen had announced it as a general feature of the Russian River 

 system, in the bulletins of the Society of Naturalists of Moscow ; and 

 besides giving the result of his own observations in the region to 

 the south and west of the Ural (where, from the absence of any con- 

 siderable mountain system, and the general flatness of the country, the 

 action of this cause would be little liable to be masked by local in- 

 equalities of a geological origin), cites the authority of M. Blode, as 

 having observed the same thing in southern, M. Bouiller in central, 

 and Baron Wrangell in northern Russia ; Tschichatscheff, in central 

 Siberia ; and Blasins, and other geologists, in many other parts of Rus- 

 sia, adding that a feature so uniform, and prevailing over so vast an 

 extent of territory, must evidently be due to some uniform and general 

 cause. This cause he seeks, accordingly, in geological upheavals and 

 dislocations, though evidently at a loss to perceive how such upheavals 

 should have affected always the right bank of the river, without regard 

 to the point of the compass toward which the water flows. 



The same cause which throws the water of a river preferentially against 

 its right bank must act of course in every case where masses of matter 

 are in motion along definite lines of route, and therefore on railways, 

 wherever there is a double line of rail for up and down traffic. For in 

 such the right-hand rail on each line will be most worn ; and, in all cases, 

 the flanges of the right-hand wheels of the carriages will suffer most 

 by abrasion, and a greater probability (though in a very slight ratio) 

 will exist of running off the rail to the right than to the left side of the 

 line of travel, especially in lines running due north and south. 



CURIOUS DEVIATIONS OF THE PLUMB-LESTE. 



The deviations of the plumb-line at different points of the earth's 

 surface from the general law of perpendicularity to the surface of a 

 spheroid, is usually considered as owing to the lateral attraction of 

 mountain masses drawing it toward them ; but a singular case of a 

 quite contrary nature has been brought to notice in the immediate 

 vicinity of Moscow, where the operations of the Russian geologists, 

 confirmed by the subsequent and more recent . researches of M. 



