320 Homer's Geological Address. 



they met with in their progress, and graved the furrows and 

 striae. We as yet know little of the existence, at great depths, 

 of submarine currents, or of their power of transporting heavy 

 materials. Sir R. Murchison, referring to the generation and 

 power of what Mr Scott Russell calls a wave of the first order, 

 or " the wave of translation,'* and to the application of Mr 

 Russell's researches and theory by Mr Hopkins, in his paper 

 " On the Elevation and Denudation of the district of the Lakes 

 of Cumberland and Westmoreland,"* considers that all the 

 phenomena of the boulder formation and drift of Northern 

 Europe (not including the erratic blocks) may be accounted for 

 by the action of such waves. But a sudden paroxysmal move- 

 ment of the bed of the sea is a necessary condition for the 

 production of a wave of translation. Mr Hopkins says, " If 

 the elevation were sufficiently gradual, no sensible wave would 

 result from it ; but if it were sudden, the surface of the water 

 above the uplifted area would be elevated very nearly as much 

 as the area itself, and a diverging wave would be the conse- 

 quence ;" and that " there is no difficulty in accounting for a 

 current of twenty-five or thirty miles an hour, if we allow of 

 paroxysmal elevations of from 100 to 200 feet ;" and he adds, 

 that "if the extent of country be considerable, the elevation 

 might occupy several minutes, and still produce the great wave 

 above described.'' It is to be observed that the wave would 

 be diverging, and therefore the currents would not be limited 

 to one direction. But however great the power of transport 

 of the sudden wave might be, its action would be transient, 

 and we must therefore suppose, either that the whole pheno- 

 mena were produced by one sudden elevation, or that there 

 was a succession of paroxysms. Whether such sudden violent 

 transport, such tumultuous hurrying along of the blocks, gravel, 

 and sand, be consistent with the forms and arrangements of 

 the detrital matter, the long " trainees," " the widely spread 

 and finely laminated sands,'^ and the included fragile shells, 

 can only be determined by special observations directed to such 

 an inquiry. It does not appear at all consistent with the for^ 

 mation of the detritus of local origin, that which constitutes 



•* Proc. Geol. Soc, vol. iii., p. 757. ' 



