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SCIENCE 



[N. S. Vol. LII. No. 1354 



hundreds of bodies, in distant space, whose 

 rays of light we have not perceived. The 

 spectrograph has shown with certainty that, 

 of the naked-eye stars, one in four on the 

 average is not the single star which it appears 

 to be to the naked eye, or when viewed in the 

 telescope, but that it is a double sun, the two 

 bodies revolving continuously about their mu- 

 tual center of mass. These hundreds of binary 

 systems are so far away that even under the 

 highest telescopic magnification they blend 

 into a common and essentially mathematical 

 point. It is the expectation that the future, 

 possibly the present century, will establish that 

 one star in three, on the average, is a double 

 solar system. It may even prove to be the 

 trU.th that our solar system, consisting of one 

 great central sun and many attendant planets, 

 is not the average and prevailing system, but 

 is the exception and not the rule. However, 

 we have no good reason to doubt that tens of 

 thousands, more probably tens of millions, of 

 distant suns are the centers of planetary sys- 

 tems, and that countless planets are the abode 

 of life. As our sun is but one of hundreds of 

 millions of suns, it is absurd and essentially 

 inconceivable that oiu- planet, or two or three 

 of our planets, should be the only bodies 

 throughout the universe supporting life. It is 

 vastly more probable that if our vision could 

 penetrate to other stellar systems, lying in all 

 directions from us, we should there find life 

 in abundance, with degrees of intelligence and 

 civilization from which we could learn much, 

 and with which we could sympathize. The 

 spectroscope proves absolutely that dozens of 

 chemical elements in the earth's surface strata 

 exist in our sun: that iron, the silicon of our 

 rocks, hydrogen, helium, magnesium and so 

 forth exist in the distant reaches of our stellar 

 system. If there is a unity of materials, unity 

 of laws governing those materials throughout 

 the universe, why may we not speculate some- 

 what confidently upon life universal? 



In the days of my youth, here in northern 

 Ohio, the opinion prevailed throughout the 

 community, and widely over the earth, that 

 comets were the forerunners of wars, plagues 

 or other forms of dire distress. Did not the 



great comet of 1811 herald the war of 1812, 

 and that of 1843 the Mexican War and Do- 

 nati's comet of 1858 our Civil War? Even in 

 the twentieth century the fear that a comet 

 may collide with the earth and destroy its in- 

 habitants comes to the surface, here and there, 

 every time a comet is visible to the naked eye. 

 The findings of astronomers concerning these 

 visitors to our region of space have taught 

 that we have nothing to fear from them, and 

 that their close approachqp may be welcomed, 

 for they are interesting members of our sun's 

 family. They revolve around our sun as the 

 planets do, and render unto it homage and 

 obedience. It is undoubtedly true that the 

 earth has plunged through the tails of comets 

 many a time and without appreciable effects 

 ujwn our health and happiness. In fact, the 

 inhabitants have at the time been blissfully 

 unaware of the passeige. It is true that a col- 

 lision of the condensed head of the comet with 

 the earth, is not impossible ; it may some time 

 occur; but comprehensive studies of this ques- 

 tion, based upon observational data concerning 

 many of these bodies, lead indubitably to the 

 conclusion that we must not expect these col- 

 lisions to occur, on the average, more than 

 once in 15 or 20 million years. The so-called 

 shooting stars, which we have all observed in 

 the night sky, are in many cases, perhaps in all, 

 though we do not know, the burning of minute 

 pieces of comets which have disintegrated and 

 disappeared as comets forever from our sight. 

 Colliding with the earth, rushing through the 

 upper strata of our atmosphere with speeds up 

 to 40 or more miles per second^ the frictional 

 resistance of the air heats them to the burning 

 point, and' they are turned into ashes and the 

 vapors of combustion. A very few get through 

 to the earth's surface and are found and placed 

 in our museums. It is not certain that any 

 of those in the museums are parts of disinte- 

 grated comets, but some of them probably are. 

 The number of small foreign bodies which 

 collide with our planet every day is very great; 

 a conservative estimate is 20,000,000. Except 

 for our beneficent atmosphere man would 

 suffer many tragedies from the bombardment. 

 There is reason to believe that the earth is 



