One source of the continued acquisition of energy by our sun, whose value is hard to estimate, is the shooting stars, or meteors, which constantly fall into it. Astronomical records show that, from the earth alone, no less than twenty million shooting stars are daily within the limits of vision, and inasmuch as the solar system is moving with a velocity of some twenty miles per second through space, it will be seen that the number of meteors which would come within the influence of the sun, being as it is about one and one-third million times the volume of the earth, would be practically infinite. What then must be said of the amount of energy acquired by the sun from these, although each meteor may have a mass of but a few grams, and perhaps may be only several hundred miles away from its successor? It is clearly demonstrated that, if no such additions of energy were received by our sun, in about ten million years its diameter would be reduced to one-half of what it is now, and its mass, where now it exists as a gas, would then become a solid, at least upon the surface, and the quantity of heat received by the earth would become so small that life here, as we know of it, would be an impossibility. But if it be granted that the sun annually gathers, by its gravitative attraction, a combined mass of matter equal to the one-hundredth part of our earth, at a distance away from its center equal to the main radius of the earth's orbit, the energy dissipated by its radiation of heat at its present rate would be accounted for, while the sensible heat of the sun would not diminish, and the supply would be kept up indefinitely. That such additions of mass are made, there can be no doubt, but as to their quantity, we cannot, with our present knowledge, even hazard a guess. In speaking of the solar heat and man's dependence upon it in a constant definite quantity, as one of the conditions of his existence, perhaps it will give us some just appreciation of his place in nature when we consider that the earth receives somewhat less than one two-billionth part of the heat radiated away by the sun, and while this expression makes the quantity which we receive seem rather small, it is, nevertheless, large enough annually to melt a layer of ice one hundred and seventy-five feet thick--all over the surface of the earth, and is a little more than one six-thousandth part of the quantity of heat which would be generated by the burning of a mass of coal as large as the sun.