174 CARNEGIE INSTITUTION 



is illustrated by the rise, within the last quarter of a century, of 

 physical chemistry and astrophysics. Van't Hoff, Ostwald, and 

 others, seeing that there was a great unoccupied field between 

 physics and chemistry, began the occupation of it. The great results 

 reached by these men placed their names very high in the roll of 

 those who have contributed fundamental ideas to science. More 

 recently we have seen the mar\'elous rise of astrophysics. The scien- 

 tific fruits yielded by occup^dng the ground between astronomy and 

 physics have not been less important than those which have come 

 from occupying the ground between chemistry and physics. 



The purpose of a geophysical laboratory is to take possession of 

 the vacant ground between geology and physics and geology and 

 chemistry. So long as geology remained a descriptive science it had 

 little need of chemistrj^ and physics; but the time has now come 

 when geologists are not satisfied with mere descriptions. Thej' desire 

 to interpret the phenomena they see in reference to their causes — 

 in other words, under the principles of physics and chemistry. If 

 this be done the intermediate ground between geology and ph^'sics 

 and chemistry must be occupied. This involves cooperation between 

 physicists, chemists, and geologists. If such cooperation be under- 

 taken in a systematic way upon an adequate scale, it is believed that 

 there will be a greater revolution in the science of geology than it 

 has hitherto undergone. Instead of being a descriptive science, it 

 will be a science reduced to order under the principles of phj^sics and 

 chemistrj^ or, more simply, under the laws of energ>\ It is also 

 believed that incidentally the sciences of physics and chemistry will be 

 enormously advanced by the investigations undertaken. 



As showing the advantages which may come from the cooperation 

 of geologists with scientists in the other branches, there may be 

 mentioned one kind of cooperation, which has already begun upon 

 a considerable scale, which does not necessarily require a laboratory : 

 cooperation between geologists and mathematicians. In the past, 

 many mathematicians have taken up geological problems, but usually 

 their discussions have been unsatisfactory because important geolog- 

 ical data were omitted from their premises. But by cooperation 

 with a geologist the mathematician is enabled satisfactorily to apply 

 his mathematics to geological problems because he has a full state- 

 ment from a competent geologist as to the geological factors which 

 enter into the problems. The mathematician publishes his results 

 and gets full credit for his work. The geologist then applies these 

 results to his geological problems. Thus by action and reaction 



