The above will be looked upon as an unwarrantably bold assertion; but a careful study of, or attention to, what is taught in the most advanced works on the solar system, even in science generally, will show it to be perfectly true. It is not only true, but the consequences of its being true have been much more serious than will be readily believed. In our own endeavours to understand what we had been reading, we have seen that some of the notions presented to us were only half formed, and that they have led to theories being founded which could never have been entertained at all had they been thoroughly studied out. More than that, they have prevented the truth from being arrived at in the fundamental conceptions of the construction of the earth, and, as a natural consequence, of the whole solar system, perhaps even of the whole universe. There are probably many, even a great many, people who have arrived at the same conclusions as we have, but as far as it has been in our power to search into the matter, we have met with no attempt from any quarter to put an end to this defect in the literature of science; perhaps because the work has the appearance of being too great to be readily undertaken, and also because it may be thought that there is little to be gained by it--as all is sure to be set right through time. But, as we believe that it will be beneficial immediately, in the case of the earth and solar system at least, we shall first attempt to show what are some of the defects alluded to, and then what knowledge may be acquired through their removal. CHAPTER I. PAGE 18 The bases of modern astronomy. Their late formation 19 Instruments and measures used by ancient astronomers 20 Weights and measures sought out by modern astronomers 20 Means employed to discover the density of the earth. Measuring by means of plummets not sufficiently exact 21 Measurements with torsion and chemical balances more accurate 22 Sir George B. Airy's theory, and experiments at the Harton colliery 23 Results of experiments not reliable. Theory contrary to the Law of Attraction 24 Proof by arithmetical calculation of its error 26 Difficulties in comparing beats of pendulums at top and bottom of a mine 27 The theory upheld by text-books without proper examination 28 Of a particle of matter within the shell of a hollow sphere. Not exempt from the law of Attraction 29 A particle so situated confronted with the law of the inverse square ofdistance from an attracting body. Remarks thereon 31 It is not true that the attraction of a spherical shell is "zero" for a particle of matter within it