612 THE POPULAR SCIENCE MONTHLY. 



THE SOLAR SYSTEM AND ITS NEIGHBORS.* 



By C. B. WARRING, Ph. D. 



ASTRONOMERS say that this world of ours, which seems to us so 

 large, is in ^fact so small in comparison with the sun and stars, 

 that its presence or absence is, to the universe, a matter of incon- 

 ceivably small importance ; and that, even in its own system, it would 

 hardly be noticed by an eye capable of taking in at one view the sun 

 and its attendant planets. 



Sir John Herschel gives the following illustration of the size and 

 distance of these bodies : " Choose," he says, " any well-leveled field. 

 On it place a globe two feet in diameter ; this will represent the sun ; 

 Mercury will be represented by a grain of mustard-seed on the circum- 

 ference of a circle 164 feet in diameter for its orbit ; Venus, a pea in 

 a circle of 284 feet in diameter ; the earth, also, a pea on a circle of 430 

 feet ; Mars, a rather large pin's head in a circle of 654 feet ; Jupiter, 

 a moderate-sized orange in a circle nearly half a mile across ; Saturn, 

 a smaller orange on a circle of four fifths of a mile ; Uranus, a full- 

 sized cherry upon the circumference of a circle more than a mile and 

 a half ; and Neptune, a good-sized plum on a circle two and a half 

 miles in diameter." 



If our earth were struck out of existence, it would hardly be missed 

 from such a system. But this is far from the extreme measure of our 

 littleness. The evening sky is studded with stars. Between us and 

 them is empty space. As we look across it, the distance does not 

 seem so very great, and even astronomers were" long in learning how 

 great it is, and how utterly isolated the sun with its train of planets 

 is from even the nearest star. Keeping the same scale as before, in 

 which our inconceivable distance from the sun, 92J millions of miles, 

 was reduced to a dozen rods or so, and then setting out to visit our 

 neighbors, if we are lucky enough to turn our steps to the nearest, we 

 find before us a journey of nearly 9,000 miles. Had we directed our 

 course to any other of the stars, our road would have been many thou- 

 sand miles longer. There are stars from which light requires 6,000 

 years to reach our globe ! 



Had we gone toward one of them, our journey on the same infinite- 

 ly reduced scale would have taken us nearly 18,000,000 miles before 

 reaching our goal. 



. Even this scale gives distances too vast. Let it be changed. Let 

 the sun shrink to a point T g- of an inch in diameter. The distance to 

 the sun, 92| millions of miles, would be reduced to nearly one inch. 

 The earth would be only y^J-g-g- f an i ncn m diameter, requiring 



* Read, January 13, 18S0, before the Poughkeepsie Society of Natural Science. 



