CHAPTER IX.

Inquiry into the Interior Construction of the Earth--_continued_ 165 The earth gasiform at one period. Density including the moon may have been 1/10,000th that of air. Must have been a hollow body. Proofs given 166 Division of the mass of the earth alone into two parts 169 Division of the two masses at 817 miles from surface 171 Reasons why the earth cannot be solid to the centre 172 Gasiform matter condensing in a cone leaves apex empty 172 Proportions of the matter in a cone 173 Calculations of the densities of the outer half of the hollow shell of the earth. Remarks upon the condensation 174 Calculations of inner half of the hollow shell 175 Remarks upon position of inner surface of the shell 177 Calculations of the same 179