3Iesozoic and Cc&nozoiG Geology and Palaeontology. 143 



constitutes the interior of the earth, we are entirely ignorant ; few of 

 our mines penetrate deeper than one fifty -thousandth part of the 

 earth's diameter, under the surface, and none of them go beyond one 

 twenty-five thousandth part of that diameter: it would appear, there- 

 fore, that any mere supposition concerning the actual and present state 

 or the nature of those substances, which form the interior of the earth, 

 is unsupported, as 3'et, by an}' reasonable analogy : and that all con- 

 jectures, concerning former changes, partial or total, in the nature and 

 structure of those substances, are removed still farther from anj-thing 

 analogous, in our present state of knowledge." 



"The earth being flattened, at the poles, does not necessarily imply 

 its former fluidity. We may be permitted to doubt the analogy between 

 our experiments on bodies moving, in our atmosphere, and the earth's 

 motion in space; our total ignorance of the nature of the fluid, which 

 occupies what is usually called space, tends to render the analogy in- 

 conclusive.'' 



" May not the mode of casting patent shot be considered as an ex- 

 periment, on the form which liquid bodies would take by a rotar}' 

 motion? A drop of melted lead let fall from the height of 200 feet is 

 completely globular, and not flattened at the poles; the lead might 

 be thrown with force from the top of the tower, which would imitate 

 the centrifugal force, as gravitation does the centripetal force, and 

 make the experiment more analogous." 



" The supposition that the earth was in a fluid state, when it took 

 its present form, leads to the supposition that it was always so; and 

 that fluidit}^ was the original state of the earth, kept so by all the 

 general laws and order of nature, all of which general order and laws 

 of nature must be totally changed before the earth would take a solid 

 form." 



"On the supposition that the earth, previous to its fluid state, had 

 existed alwaj's in a solid state, and that some creation or accident 

 produced the fire or water necessary to its liquefaction, we have, in 

 that case, first to suppose that the order and nature of the general 

 laws, which had kept it alwa^'s in a solid state, were totally- changed 

 to produce a fluid state ; and that another change, in the general laws, 

 which produced and kept it in a fluid state, must have taken place pre- 

 vious to its having become again solid." 



•' It may be doubted whether the uniformit}^, order and regularity of 

 the general laws of nature, which have at any time come within the 

 limits of our observation, can warrant a supposition founded on such 

 complete changes in the mode of action." 



