POWER OF WAVES OF TRANSLATION EXPLAINED. 
533 
them by Mr. Hopkins to geological phenomena, have shown that elevations of 
continental masses of only fifty feet each, from beneath an ocean having a depth 
of 300 or 400 feet, would cause the most powerful divergent waves, which could 
transport large boulders to great distances i? 
Granting, however, that water has exercised all the influence attributed to it 
by these philosophers, the existence of intervening deep valleys, transverse to the 
direction which the erratic drift has taken, and the subangular state of many of 
the far-borne blocks, must prevent our adoption of this agency only, as explaining 
all the conditions of the problem. Strengthened by having ourselves found marine 
shells associated with erratic blocks, we have previously expressed our agreement 
with Mr. Lyell, that the bottoms of icebergs grating upon submarine rocks may 
occasionally have furrowed, scratched, and polished their surfaces, precisely in the 
1 “ In describing the motion of such masses of water, Mr. Hopkins invokes the aid of those waves of 
translation whose properties have been reduced to laws by the ingenious and valuable researches of 
Mr Scott Russell, and who, giving us measures of their relative velocity and power, has brought forward 
exact proofs of the transference by them of solid bodies immersed in water. Such waves have in fact been 
generated by the experiments of Mr. Scott Russell, exactly in the same way as Mr. Hopkins supposes 
waves to have originated on the great geological scale. These experiments prove, that a sudden eleva- 
tion of a solid mass from beneath the water, causes a corresponding elevation of the surface of the fluid, 
which infallibly produces a wave of translation of the first order. Now this wave is termed one of trans- 
lation, because it is found not to rise and fall like common waves, but wholly to rise and maintain itself 
above the level of the water. Arguing that this wave is propagated with a velocity which varies with 
the square root of the depth of the ocean, Mr. Russell determines the velocity of wave transmission ; but 
what is of most importance to the geologist is, that the old idea of the agitation and power of waves ex- 
tending a little way down only in the sea, is found to be not true as touching waves of translation ; for 
Mr. Scott Russell has ascertained that when they are in action, the motion of the particles of the water 
is nearly as great at the bottom as at the top. He further shows, that the body moved at the bottom, is 
not rolled backwards and forwards as by a common surface-wave, but has a continuous forward motion 
during the whole transit of the wave’s length. A complete transposition does therefore result from the 
wave transit ; and the wave of translation, says Mr. Scott Russell, may be regarded as a mechanical 
agent for the transmission of power as complete and perfect as the lever or the inclined plane. 
“ Arguing from these remarkable data, and applying them to our geological phsenomena, Mr. Hopkins 
states, that currents of twenty-five and thirty miles an hour may be easily accounted for, if repetitions of 
elevations of from 160 to 200 feet be granted; and with motive powers producing a repetition of such 
waves, this author has no difficulty in transporting to great distances, masses of rock of larger dimen- 
sions than any boulders in the North of England.” See Mr. Murchison’s Anniversary Address to the 
Geological Society (anno 1843), Proc. Geol. Soc. vol. iv. p. 9. Mr. Scott Russell’s views were first ex- 
plained to the Meeting of the British Association for the Advancement of Science in 1843, and are now 
preparing for publication. 
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