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what means the most evident phenomenon might have been 
accomplished, then to collect all the evidence connected with 
the effects, and lastly, after putting aside our preconceived 
opinions, to consider which of the many explanations is 
most in accordance with the actual facts before us. 
To the scientific minds of the middle ages, few subjects 
appeared more unnatural and more ridiculous than that the 
earth should move. Yet actual facts were in favour of this 
movement. And these individuals forgot that whilst they 
rejected as absurd the theory of the earth's movement, they 
admitted as sound and probable, the theory that the whole of 
the fixed stars, the sun and the planets, rushed round the 
earth with a velocity a thousand times greater than that 
assumed by the new theory for the earth. Thus, it not 
unfrequently happens, that a truth, if novel to our minds, 
is rejected from its supposed absurdity, whilst a falsity which 
we have long tacitly acknowledged as a truth, is looked 
upon as quite in accordance with nature. 
Whenever any change of level is spoken of, it is necessary 
to refer to some fixed point as a datum ; in the present 
inquiry this datum will be the centre of the earth. That 
the same land should rise, then sink, then rise, and so on, is 
not by any means necessary to produce a change in the 
relative position of land and sea. Let us take an example : 
Suppose that the whole surface of Africa were to gradually 
sink, so that it approached 10 miles nearer the centre of the 
earth, (this distance being merely taken for illustration), in 
consequence of water finding its own level, there would be a 
transfer of a body of water from the whole ocean, equal in 
cubical contents to the area of the continent of Africa, and 
10 miles deep. This withdrawal of water would leave a vast 
area of land, in many parts of the world where sea now 
exists, — such, for instance, as the Newfoundland bank, the 
English Channel, the plateau across the Atlantic, &c. 
