ADDRESS OF THE PRESIDENT OF THE MICHIGAN 

 ACADEMY OF SCIENCE. 



Delivered March 28, 1917, at the Auditorium, 

 Natural Science Building. 



THE MAKINCi OF SCIENTIFIC THEORIES*. 



liY WILLIAM II. IIOBBS. 



Tlu' ancient Hebrews conceived the earth to be a disk liemmed in on 

 all sides by mountains and surmounted by the crystal dome or firmament 

 of the "heavens." This covered disk floated upon "the waters under the 

 earth" and from the "windows of heaven" waters were poured out upon 

 the "thirsty earth" from another reservoir which was above the firma- 

 ment. To the denizen of the humid temperate regions it is perhaps a 

 little difficult to see how this theory could have come into existence. The 

 rains with which he is so familiar are showers, and they suggest not so 

 much windows in tlie sky as they do a ceiling with innumerable perfora- 

 tions or some other glorified sprinkling device. To the Children of 

 Israel the phenomenon of showers was unknown, for the rains to wliich 

 they had become accustomed both during their wanderings in the desert 

 of Sinai and in Palestine were of the local downpour or cloudburst type, 

 the characteristic precipitation of the arid lands. So also their country 

 was one in which earthquakes have been frequent, and they were not 

 unaccustomed to seeing the earth open and water shoot upward from the 

 fissures in much the same manner that it spurts into the hold of a ship 

 from the opening of a seam. This oft-observed phenomenon is with 

 little doubt responsible for the conception of the "waters under the 

 earth" referred to in the twentieth chapter of Exodus. We see, there- 

 fore, that this crude tlieory of the world which was held by the early 

 Hebrews and which appears to us so fantastic, was, after all, based 

 upon facts, but like many theories which have followed it, upon too 

 small a body of fact to supply a firm foundation. 



It has often been said that the theories so tenaciously held by one 

 generation are abandoned by the next. To a large extent this has been 

 true of the past, and the explanation is in part that scientists are not 

 less fallible than others, but are subject to like limitations in prejudice, 

 in undue reverence for authority, in regard for the science vogue of 



*Printed also in Science 45:441-451. May II, 1917. 

 I9th Mich. Acad. Sci. Rept. 1017. 



