1882. 81 Trans. N. Y. Ac. Sct. 
from the earth, and after the cooling of the globe had produced the 
precipitation and accumulation of ocean waters, the attraction of the 
moon acting inversely as the cube of the distance, produced tides of 
stupendous altitude as compared with any now witnessed. For exam- 
ple, supposing the earth to have been largely covered with water, when 
the moon was 40,000 miles away, one sixth of its present distance, its 
attraction must have been thirty-six times as great as at present, and 
its efficiency as a tide-producer two hundred and sixteen times as great 
as atpresent. This would give, for an average tide corresponding to a 
tide of three feet now, a height of 648 feet. 
Prof. Ball pictures to his audience the effect of a tidal wave of this 
height rushing over and retreating from all shores twice in each 
short day, and jus'ly ascribes enormous destructive power to such an 
agent. This condition of things he fancies to have existed forty or fifty 
millions of years ago, perhaps when the first sedimentary rocks now 
known, the old Palzozoic and Archzan strata, were deposited ; and since 
in certain localities there were accumulations of mechanical sediments, 
shales, sandstones, etc., to the depth of several miles in these ages, 
they are explained to be the result of the action of these tremendous 
tides. 
Prof. Ball further ascribes to this agent the greater part of the 
changes that have taken place on the earth’s surface, and claims to 
have revealed to geoiogists in this discovery the most important tactor 
in all their data for writing the ancient history of the globe, and one of 
which they seem to have been strangely ignorant. 
Now, all this is exceedingly interesting. and important, zf ¢rue; but 
in behalf of the geologists, I venture to report certain facts which seem 
to be quite irreconcilable with it. There can be no question that a 
tide of 600 to 1000 feet in height, sweeping over all shores and lowlands 
twice a day, would be a most powerful destructive and creative engine ; 
and it may be conceded at once that its potency in remodeling the 
earth’s surface would far surpass any agent of change now in action. 
Let us imagine for amoment what the effect of a tide two hundred 
times greater than the present would be, if called into existence on the 
Atlantic coast of America to-day. The height of the tide along our 
coast varies from nine to twelve feet, and we mav say the average is 
ten. This would give a height of two thousand feet to the tide pro- 
duced by the moon if only 40,000 miles distant. The effect of such a 
flood would be so tremendous that it can hardly be realized. The whole 
littoral plain, two hundred miles wide, which forms the topographical 
margin of the continent, now half sub-marine, half sub-aerial, would be 
swept twice a day witha wave not less than a thousand feet in height ; 
and a bore fifty times as high as that of the Hoogly would rush up the 
