„ time, Sir Andrew C. Ramsay on, 67 Geology, testimony of, in regard to age of sun’s heat, 39 Glacial epoch, age of the earth as determined by, 64 „ epochs, influence on denudation, 46 Gravitation does not account for the heat required, 106 „ does not account for motion of the stars, 105 „ insufficient to account for heat of nebulæ, 27 Groombridge 1830, motion of, 15 „ not an eject, 106 „ Prof. Newcomb on motion of, 15 Grove, Sir W. R., on the pre-nebular condition of matter, 78 Haeckel, Prof, on geological time, 67 Haughton, Prof., method of estimating rate of denudation, 50 Heat, age of the sun’s, 37 Helmholtz on age of sun’s heat, 35 Huggins, Mr., and Dr. Miller on spectra of nebulæ with one nitrogen line, 84 Hull, Prof., on denudation of Pendle Range, 60 „ on examples of enormous faults, 54 Humphreys and Abbot on sediment of the Mississippi, 40 Hunt, Dr. T., on the pre-nebular condition of matter, 85 „ on universal atmosphere, 86 Huxley, Prof., on geological time, 65, 66 Hypothesis, value of, 70 “Impact Theory,” why so called, 2 „ in relation to theories of pre-nebular condition of matter, 102 „ removes difficulties regarding origin of heat, 108, 109 ε Indi, motion of, 16 King, Mr. Clarence, on the Wahsatch Fault, 59 Lalande 21185, motion of, 16 „ 21258, motion of, 16 Laplace, M., on the heat of the solar nebula, 30 Lavoisier, M., on simpler forms of matter, 86 Lesley, Mr. J. P., on a fault in the Appalachians, 57 „ on fault in East Tennessee, 58 Liveing and Dewar on dissociation of chemical elements, 83 Lockyer, Mr., on arrangement of the planets according to density, 25 „ nebulæ with solid matter in a gaseous mass, 20 Lockyer, Mr., on essential condition of solar nebulæ, 25 „ on hypothesis, 70 „ on number of meteorites, 103 „ on outburst of stars, 33 „ on “sorting” of the chemical elements, 25 Lodge, Prof. O., on ethereal origin of matter, 87 „ on the pre-nebular condition of matter, 87 „ on vortex atoms, 88 Logarithmic law of atomic weights, 100 Lyell, Sir Charles, on denudation of the Mississippi basin, 44 Macvicar, Dr., on ethereal origin of matter, 87 Matter not probably eternal, 112 Mendelejeff, Prof., on Periodic Law, 96 Meteorites, number greatly exaggerated, 103 „ probable origin of, 12 „ Sir H. Roscoe on constitution of, 12 „ Sir W. Thomson on, 12 Mill, Mr. J. S., on hypothesis, 70 Miller, Dr., and Mr. Huggins on spectra of nebulæ with one nitrogen line, 84 Mills, Dr., on Polymerisation, 95 Morris, Mr. Charles, on the pre-nebular condition of matter, 75 Nebulæ, broken fragments in a gaseous mass, 19 „ cometic, 22 „ condensation insufficient to account for heat of, 27 Nebulæ condensation, last condition of, 30 „ first condition of, 19