30 NINETEENTH REPORT. 



of the earth's surface a corresponding excess of mass ; that this theory 

 lias been set up without due regard to the dominating effect of any hidden 

 masses of unusually high density which may lie near the observing 

 station. This view seems now to have found confirmation in recent 

 studies carried out by the United States Coast and Geodetic Survey. 

 I may perhaps best illustrate what is here meant by the use of an example 

 taken from a related field of study. If one should ascribe the strong 

 magnetic attraction which is exercised by local masses of iron ore in the 

 Northern Peninsula of ^lichigan to the effect of such an extended system 

 of smaller masses distributed throughout a large district, as might pro- 

 duce the same effect at a given station, the error would be of the same 

 nature as that which must result from ignoring the effect at the gravity 

 stations of any local and very dense masses which may be hidden beneath 

 the surface. 



Does prejudice, eitlier national or racial, ever influence the thinking of 

 men of science? I ask you to look back over the history of the past 

 two and a half years and for the answer examine some of the state" 

 ments which have been signed by men who were counted among the 

 master scientists of their generation. These sweeping statements were 

 many of them false ; and if not known to be by those who subscribed to 

 them, it is clear that an unbiased inquiry must either have revealed the 

 truth or have indicated the necessity of witliholding a verdict. This 

 debacle of science which came at the outbreak of the present war is one 

 not easily to be retrieved. 



If I have succeeded in my endeavor, I have shown that scientific 

 tlieories as they are constructed even today with the aid of all modern 

 equipment and inheritance, may contain fatal elements of weakness 

 though they be ])romulgated by scientific men of the highest rank and 

 attainments. Fortunately the student of science today enjoys an inde- 

 pendence which was never vouchsafed him in the past, when the learner 

 was by tlie conditions under which he studied an advocate of the doctrines 

 of his master. Tliere are today no dictators in science such as were 

 Werner in Germany, de Beaumont in France, Murchison in England, or 

 Agassiz, the "pope of American science." For what he accepts and 

 teaches the student of science is today responsible, and it devolves upon 

 liim not merely to examine each theory as regards its inherent plausibility 

 and tlie degree to which it has been confirmed, but to inquire also into 

 tlie human and other factors which have entered into it or which have 

 accounted for its acceptance into the body of doctrine of science. 



It has seemed to me. that the excessive stress which in our science 

 training we now lay upon the careful balancing of evidence, has in a 

 measure taken away our capacity for making decisions. The cult of 

 being open-minded has been elevated into a fetich, with the result that 



