GEOLOGY. 263 



of this law, I have been very much indebted to the able paper of Mr. 

 J. Scott Russell, on waves, in the proceedings of the British Associa- 

 tion. It may be said here generally that the motion of translation, or 

 motion of the water particles in the positive wave of the first order of 

 Mr. Russell's classification, is such as to make that wave ' a vehicle 

 for the transmission of mechanical force.' This is the form of wave 

 that follows upon the destruction of the waves of the sea upon an allu- 

 vial coast. The wave of the sea is of the second order ; in passing 

 from the second to the first order, the motion of the particles changes 

 from the motion of oscillation to that of translation. The matter trans- 

 ported by the current of the flood tide is subjected to this wave action ; 

 the particles of water and the suspended matter being projected for- 

 ward at the moment of disintegration with a mechanical power 

 proportioned to the height of the wave. The substances beneath the 

 breaking wave also receive a shock tending to force them further up 

 the beach. It is under the control of this law that the vast material 

 of the tertiary and drift periods, which constitute the flesh and muscles 

 of the great continents, have been saved from wasteful diffusion in the 

 depth of the ocean, and have been grouped around their original 

 sources. It may be assumed to be one of the subordinate fundamental 

 laws of the globe." 



After the reading of Lieut. Davis' note, Prof. Bache stated that he 

 had directed the officer engaged in the hydrography of Charleston 

 harbor, to take up a considerable bulk of water at different periods of 

 the ebb or flood tide, with the sand mixed in it, so as to determine the 

 relative amount of deposit in equal quantities of water at different pe- 

 riods of the tide. The examination was not completed, but Lieut. Maffit 

 had reported that the water, during the flood, contained a very much 

 greater amount of sand than during the ebb. The sand of the bar, 

 during the flood tide, is, as termed by sailors, "alive," a fact which 

 confirms signally the proposition of Lieut. Davis. 



ON THE GEOLOGICAL AGENCF OF THE WINDS. 



THE following is an abstract of a paper, read at the American Asso- 

 ciation, Albany, by Lieut. M. F. Maury : 



In the recent survey of the Dead Sea, by Lieut. Lynch and others, a 

 level was run from the surface of the lake to the Mediterranean, which 

 showed the surface of the Dead Sea to be about 1300 feet below the 

 general sea level of the earth. In seeking to account for this great 

 difference of water level, the geologist examines the neighboring region, 

 and calls to his aid the forces of elevation and depression which are 

 supposed to have resided in the neighborhood. He points to them as 

 the agents which did the work. But is it necessary to suppose that 

 they resided in the vicinity of this region? May they not have been, 

 if not in this case, at least in the case of other inland basins, as far re- 

 moved as the other hemisphere ? This is a question which I do not 

 pretend to answer definitively. But the inquiry as to the geological 

 agency of the winds, in such cases, is a question which my investiga- 

 tions have suggested ; and I therefore present it as one which, in ac- 



