THE 



POPULAR SCIENCE 



MONTHLY 



APRIL, 1911 



THE GENESIS OF THE LAW OF GRAVITY 



Bt Pbofessob JOHN C. SHEDD 



OLIVET COLLEGE, OLIVET, MICH. 



SCNCE the earliest ages man has been interested in the world outside 

 of himself. Thunderstorms, waterfalls, winds, waves, fire, the 

 starry heavens have aroused his wonder, admiration or fear. 



During the earlier stages of racial development the simplest phe- 

 nomenon was explained by reference to some arbitrary power, and soon 

 gods and demigods were conceived of as presiding over the agencies 

 of nature. Later men who had wrested some of her secrets from 

 nature or had won some victory over her were exalted to the position 

 of heroes and worshipped, while their exploits, greatly magnified, be- 

 came part of the legendary history of the race. Slowly man began 

 to realize that there is a constancy about nature that may be expressed 

 in general statements. These statements were often vaguely expressed 

 as, " Xature abhors a vacuum," " Water and fire are antagonistic," 

 " There are three elements, earth, air and water " or " earth, fire and 

 water." These crude beginnings led to more careful and more sys- 

 tematic study of nature, and to more exact statements of what we 

 now call the laws of nature. 



It took long ages — perhaps we have not even yet reached the goal 

 — for man to realize that the content of his study is here objective, so 

 that the method of study must be inductive and not deductive. This 

 being the case, the conclusions arrived at must be allowed to shape 

 themselves regardless of consequences to antecedent beliefs. Thus it 

 happened that the study of nature has been for ages hampered by 

 many a prejudice and by many a "Thou shalt not" from churchman 

 and philosopher. 



Another and perhaps greater impediment than the inertia of the 

 human mind was the ravage wrought by war and time. Could each 



VOL. LXXVIII. -22. 



