DAILY INFLUENCES OF ASTRONOMY CAMPBELL. 145 



give me an idea how large our sun is? " " Well, if it were a hollow 

 shell, of its present size, you could pour more than a million earths 

 into it, and there would still be much unoccupied space between the 

 earth balls." " You say there are possibly or probably planets re- 

 volving around many of the cluster stars?" "Yes, sir." "And 

 many of those planets may be inhabited?" "Yes, sir." "Well, 

 then, I think it does not matter very much whether Boosevelt or 

 Taft is nominated next week at the Chicago Convention." 4 



Of course the visitor's interest in the outcome at Chicago was just 

 as keen as ever, but he had evidently received a valuable lesson con- 

 cerning man's place in nature. 



The wonders of our sun are many and most remarkable and are 

 but little known. I have referred to its enormous size. The quan- 

 tity of heat which the sun is radiating into surrounding space— to 

 the earth, to Mars, and to all other objects which intercept its rays- 

 is stupendous and not to be comprehended by the astronomer or the 

 man of affairs. It is, and has been, the. source of all the energy upon 

 which we draw, save only a negligible residual. A great quantity 

 of heat is indeed stored up in the interior of the earth, but it reaches 

 the earth's surface in such minute quantities that in all practical 

 details of life, save to those who labor in deep mines or live near 

 volcanoes or are interested in hot springs, this source of energy 

 may be neglected. If this statement should be difficult to accept, 

 let your thoughts travel to the south pole of our planet. What does 

 the interior heat of the earth do for that region ? The antarctic con- 

 tinent's perpetual covering of ice and snow is unaffected by it, nor 

 does the actually enormous quantity of solar heat falling upon that 

 continent suffice to remove the white mantle. If aught should inter- 

 vene to cut off the sun's energy from the earth for one short month, 

 the tropics would attain to a state of frigidity to which the south 

 polar continent, as now observed, would be a rose garden in com- 

 parison. 



It is the sun's heat which grows the farmer's crops, the trees of 

 the forest and all vegetation. The coal deposits upon which we 

 draw to-day for the running of trains, ships, factories, and rolling 

 mills, are but the solar energy of an earlier age, compressed, trans- 

 formed and preserved for our comfort and power. In the moun- 

 tainous regions of our land, where water can be stored in high-level 



* Following the publication of this address I learned that incidents illustrating the 

 same philosophy of life and politics occurred to Professors Frost and Barnard at the 

 Yerkes Observatory in the heat of the presidential campaign of 1908, to Professor Wood 

 at his Long Island observatory in the same campaign, and to others in later years. Com- 

 ments similar in all essential respects are made frequently by the visiting public at 

 Mount Hamilton. There is no reason whatever for doubting that the many reported 

 cases are absolutely independent of each other and are merely illustrative of human 

 nature. 



