As the earth is an extended plane resting in and upon the waters of the “great deep” it may fitly be compared to a large vessel or ship floating at anchor, with her “Hold” or lower compartments beneath the water-line filled with burning materials; and, from our knowledge of the nature and action of fire, it is difficult to understand in what way the combustion can be prevented from extending, when it is known to be surrounded with highly inflammable substances. Wherever a fire is surrounded with heterogeneous materials--some highly combustible and others partially and indirectly combustible--it is not possible for it to remain continually in the same condition nor to diminish in extent and intensity, it must increase and extend itself. That the fire in the earth is so surrounded with inflammable materials is matter of certainty; the millions of tons of coals, peat, turf, mineral oils, rock tar, pitch, asphalte, bitumen, petroleum, mineral naphtha, and numerous other hydro-carbons which exist in various parts of the earth, and much of these far down below the surface, prove this condition to exist. The products of volcanic action being chiefly carbon in combination with hydrogen and oxygen, prove also that these carbon compounds already exist in a state of combustion, and that as such immense quantities of the same fuel still exist, it is quite within the range of possibility that some of the lower strata of combustible matter may take fire and the action rapidly extend itself through the various and innumerable veins which ramify in every direction throughout the whole earth. Should such an action commence, knowing, as we do, that the rocks and minerals of the earth are but oxides of inflammable bases, and that the affinities of these bases are greatly weakened and almost suspended in the presence of highly heated carbon, we see clearly that such chemical action or fire would quickly extend and increase in intensity until the whole earth with everything entering into its composition, would rapidly decompose, volatilise, and burst into one vast indescribable, annihilating conflagration! SECTION 12. MISCELLANEA. MOON’S PHASES.--It has been shown that the Moon is not a reflector of the Sun’s light, but is self-luminous. That the luminosity is confined to one-half its surface is sufficiently shown by the fact that at “New Moon” the whole circle or outline of the Moon is often distinctly visible; but the darker outline is less, or the circle is smaller than the segment which is illuminated. From this it is easily seen that “New Moon,” “Full Moon,” and “Gibbous Moon” are but the different proportions of the illuminated surface which are presented to the observer on earth.