Geological Surveys in Great Britain, &c. 295 



part, than I can possibly foresee." In the apartments of the 

 Geological Society Smith's map may yet be seen — a great histori- 

 cal document, old and worn, calling for renewal of its faded tints. 

 Let any one conversant with the subject compare it with later 

 works on a similar scale, and he will find that in all essential 

 features it will not suffer by the comparison — the intricate anatomy 

 of the Silurian rocks of Wales and the north of England by 

 Murchison and Sedgwick being the chief additions made to his 

 great generalizations. In 1840 he died, having, in his simple 

 earnest way, gained for himself a name as lasting as the science 

 he loved so well. Till the manner as well as the fact of the first 

 appearance of successive forms of life shall be solved, it is not 

 easy to surmise how any discovery can be made in geology equal 

 in value to that which we owe to the genius of William Smith. 

 Since the publication of Smith's map, many others have ap- 

 peared — the noble compilation for England by Greenough, the 

 great original map of Scotland by Macculloch, and the yet finer 

 map of Ireland by Sir Richard Griffith. The last is a work only 

 less remarkable than Smith's in this — that, when commenced, the 

 principles of geology were established, and he followed instead of 

 leading the way. To these, of various dates, may be added the 

 maps by Professor Phillips, Sir Roderick Murchison, and Knipe, 

 and many others of districts in detail — an example first set by 

 Smith in his geological maps of counties. But the most remark- 

 able result of this appreciation of the growing value of the subject 

 was the establishment of the Government Geological Survey of 

 Great Britain, under the late Sir Henry De la Beche, to whom 

 the whole honour is due of having commenced, and for many years 

 successfully carried on, this great undertaking. From small 

 beginnings in Cornwall he gradually extended his operations, and, 

 aided by Government, he gradually trained or selected a corps of 

 skilled geologists, who, ere his death in 1855, had already mapped 

 and published nearly a half of England and Wales and part of the 

 South of Ireland. The maps employed in this survey are the 

 one-inch Ordnance sheets for the southern half of England, and 

 the six-inch maps for Ireland, the north of England and Scotland. 

 Each fault, each crop of coal, and every geological boundary is 

 traced so minutely, that on some of the roughest and loftiest hills 

 in Wales, twenty geological lines may be counted in the space of 

 an inch, corresponding to one mile of horizontal measurement ; 

 and all the country is traversed by numerous measured sections 



