276 The American Naturalist. [April, 



5. Finally, from a consideration of the above principles, the 

 geologist realizes that his work must be systematic, and that the 

 bulk of it must be done in the field. Field investigation is indis- 

 pensable. Laboratary work holds a subordinate position. 



It is safe to say that geology has advanced more rapidly 

 than any other science, and the number of those who are mak- 

 ing a specialty is steadily growing. New periodicals devoted to 

 the science are continually appearing, and its literature is 

 quite comprehensive. Very little attention was paid to it in 

 our colleges at no late date, but to-day it occupies a prominent 



The great advance which has been made is due to system- 

 atic field work, followed, by laboratory work, and the latter is 

 of but little value from a geological standpoint unless it is 

 based upon accurate field investigation. It is necessary to re- 

 duce to a practical formula the data secured in the field, and 

 to have a definite method of procedure, for without such, 

 much time is wasted, and many results that otherwise would 

 have been valuable are entirely lost. Mere conjecture must 

 not be indulged in, but " work persistently back from the seen 

 and known to the unseen and unknown," should be the 

 maxim. Conclusions must not be arrived at too hastily. 



Professor Dana once said, " I think it better to doubt until 

 you know. Too many people assert, and then let others 

 doubt." Hence, in drawing conclusions from the results of 

 field and laboratory work, be sure you are right, before giving 

 publicity to them, and if a doubt exists, state it, and be willing 

 to change your theory. Dana says, " I always like to change 

 when I can make a change for the better." 



It is obvious, from what I have said, that geology is a field 

 science. Different characteristics of the earth's surface cannot 

 always be taken into the laboratory for study at leisure, and 

 it is necessary to see the objects under study if we would ar- 

 rive at correct conclusions and fix them indelibly in our 

 minds.. Facts then become real, and we acquire a correct un- 

 derstanding in regard to the forces that have been at work 

 preparing this planet for man. 



