PRINCIPLES OF GEOLOGY. 3 



noticed by some early writers ; but the sequence was not 

 perceived until about the year 1788, when the Rev. John 

 Michell recorded the general succession of strata in the 

 Midland Counties. We are indebted, however, to William 

 Smith, justly termed the " Father of English Geology," for 

 the first clear definitions of our strata. In 1794 he proved 

 that they were (many of them) continuous over large areas, 

 that they succeeded one another in a certain order, produced 

 similar soils, and presented marked physical features. He 

 gradually learnt that they were characterized by fossils more 

 or less peculiar to them, and he thus established the fact that 

 strata could be identified in distant localities by their organic 

 remains. He also concluded that certain strata had been in 

 succession the bed of the sea, and that the fossils were remains 

 of animals that had lived and died at or near the places where 

 they are now embedded.^ 



In the mean time the philosophic deductions of Hutton 

 (1788), subsequently illustrated by Playfair, and elaborated 

 by Scrope, De la Beche, and Lyell, established the principles 

 of geology, according to which the past may be interpreted by 

 the modern changes of the earth and its inhabitants. Thus 

 Geology has come to be regarded as the Physical Geography 

 of past periods, and we are taught that the changes now 

 going on are but the continuation of the Earth's ancient 

 history. 



Our first lessons, then, are to be learnt from the alterations 

 taking place on the Earth's surface in the continual waste of 

 land by rain, rivers, glaciers, and sea ; the dispersion and 

 deposition of the material thus removed ; from the phenomena 

 of earthquakes and volcanoes, and the rising or sinking of 

 different areas. Further we have to consider the variations 

 of climate at the present time, the distribution of animal and 

 vegetable life, and the circumstances under which various 

 organisms may become buried and preserved. 



Utilizing this knowledge we find by the testimony of the 

 rocks, that physical changes like those now affecting every 

 portion of the Earth's surface, have been in operation in past 

 times through similar agents ; and that the solid ground on 

 which we live is largely made up of the consolidated mud, 

 sand, and ooze of old sea-bottoms, with the included fossilized 

 remains of the animals and plants of successive periods. 



^ Memoir of William Smith, by John Phillips, p. 141. For a full account of 

 the History of English Geology, and the influence exerted by Bufifon, Linnjeus, 

 Cuvier, Lamarck and other Continental Naturalists, see W. H. Fitton, Phil. Mag. 

 vols. i. and ii. ; A. C. Ramsay, Passages in the History of Geology, 1848 and 

 1849 ; and Lyell's Principles of Geology, vol. i. 



