* 3 2 THE POPULAR SCIENCE MONTHLY. 



heavals and cataclysms in general' is catastrophic so far as it assumes 

 that these were brought about by causes which have now no parallel." 



This was the earliest system of doctrine in geology, and was inevi- 

 table because of the narrow and false ideas concerning past time. 

 Observation accumulated evidences of vast changes in the earth's 

 crust ; it was held that the world is but a few thousand years old ; it 

 was therefore concluded that the changes must have been on a stupen- 

 dous scale, of which we have at present no experience. 



There are geologists who still hold to this view, as there were those 

 in the early history of the science who believed in vast time and slow 

 changes. Hutton, in his theory of the earth, in 1795, put forth this 

 advanced principle : " I take things such as I find them at present, and 

 from these I reason to that which must have been." It, however, be- 

 came the work of Sir Charles Lyell to elucidate and establish this doc- 

 trine, by extensive and critical investigations, as a broad and fundamen- 

 tal generalization of geological science. ZTniformitarianism, or the 

 theory which extends the present rate of terrestrial changes into the 

 past, is a problem of geological dynamics, and involves the study of 

 the totality of forces by which the earth's crust has been altered, and 

 the rocky systems formed. 



To work out so vast a subject on the basis of observation and im- 

 mediate physical data was enough to task the largest capacity, and it 

 is not surprising that Sir Charles Lyell was little disposed to venture 

 into the more speculative questions of the science. Indeed, geolo- 

 gists early insisted on the necessity of limiting inquiry to the changes 

 that have taken place since the formation of the earliest stratified rocks, 

 and crucifying the propensity to pry into the more distant origin of the 

 world. The English Geological Society tacitly forbade these specula- 

 tions, and of this procedure Mr. Huxley says: " Uniformitarianism, as 

 we have seen, tends to ignore geological speculation in this sense alto- 

 gether. The one point the catastrophists and the uniformitarianists 

 agreed upon, when this Society was founded, was to ignore it. And 

 you will find, if you look back into our records, that our revered 

 fathers in geology plumed themselves a good deal upon the practical 

 sense and wisdom of this proceeding. As a temporary measure, I do 

 not presume to challenge its wisdom ; but in all organized bodies tem- 

 porary changes are apt to produce permanent effects ; and, as time 

 has slipped by, altering all the conditions which may have made such 

 mortification of the scientific flesh desirable, I think the effect of the 

 stream of cold water, which has steadily flowed over geological specu- 

 lation within these walls, has been of doubtful beneficence." 



Mr. Huxley, in common with many other scientists, now holds that 

 the progress of geological thought must carry us beyond uniformita- 

 rianism into evolutionism. 



But Sir Charles Lyell is the farthest possible from being a narrow- 

 jninded partisan. His career offers one of the noblest examples of 



