96 NATURAL SCIENCE. 



August, 



F. A. Bather (of the Geological Department, British Museum), who, 

 trained in geology under Prestwich, have since gained distinction. 

 His field-excursions, however, were always highly appreciated by 

 many who found no time to pursue the science in after-life. 



Various papers proceeded now from his pen : he dealt with the 

 much discussed origin of the parallel roads of Glen Roy, and he 

 wrote on the agency of water in volcanic eruptions, believing that the 

 water was but a secondary cause, and that the phenomena were 

 dependent on the effect of secular refrigeration. He dealt also with 

 the problem of the thickness of the earth's crust, and published an 

 elaborate paper on underground temperatures. 



He also made a special study of the Chesil Beach, coming to the 

 conclusion that it was a wreck of an old and extensive raised beach, 

 of which a remnant still exists on Portland. His view concerning the 

 comparatively recent date of the Weymouth anticline has not, how- 

 ever, proved to be sound. 



During his term of professorship, Prestwich wrote his well-known 

 work entitled " Geology, Chemical, Physical, and Stratigraphical," in 

 two volumes, published in 1886 and 1888, a work admirably 

 illustrated. In the first volume he remarked that among geologists 

 two schools have arisen, "one of which adopts uniformity of action in 

 all time, while the other considers that the physical forces were more 

 active and energetic in past geological periods than at present." 

 Advocating this latter teaching, he felt he should be " supplying a 

 want by placing before the student the views of a school which, until 

 of late, has hardly had its exponent in English text-books." He 

 indeed protested on many occasions against the doctrine of 

 uniformity of action, both in kind and in degree. Such, indeed, was 

 the teaching of Ramsay in his Presidential Address to the British 

 Association at Swansea in 1880. That geologist referred to the great 

 changes, of which we have evidence in comparatively late geological 

 times, in the upheaval of mountain chains, and in the vicissitudes of 

 the Glacial period ; and, in regard to volcanoes, he believed that " at 

 no period of geological history is there any sign of their having played 

 a more important part than they do in the epoch in which we live." 

 Ramsay based his argument on the record of the rocks, and, leaving out 

 of consideration cosmical hypotheses, he concluded that, from the epoch 

 of our oldest known rocks down to the present day, " all the physical 

 events in the history of the earth have varied neither in kind nor in 

 intensity from those of which we now have experience." This con- 

 clusion may be taken to mean that any kinds of physical change that 

 have happened in the past since the earliest rocks were laid down 

 may happen again, and we believe that this is the real view of the 

 Uniformitarian. Mr. Teall, again, in 1893, forcibly urged the claims 

 of the Uniformitarian school, pointing out " that denudation and 

 deposition were taking place in pre-Cambrian times, under chemical 

 and physical conditions very similar to, if not identical with, those of 



