Notices of Memoirs — The Geological Survey. 307 



Museum of Practical Geology, up to the present time ; (2) a 

 description of the various kinds of work carried on by the Survey 

 in the field, in the ofiice, and in the museum, with an account of the 

 publications, issued and in preparation, by the establishment. 



I. The Origin and History of the Survey and Museum. 



The Geological Survey of the United Kingdom and the Museum 

 of Practical Geology, Jermyn Street, owe their origin to Henry 

 Thomas De la Beche — one of the most illustrious geologists of this 

 century. After various geological researches prosecuted early in 

 life on the Continent and in the South of England, he eventually 

 undertook a more detailed examination of the rocks of Devon and 

 Cornwall. Supplying himself with the maps of the Ordnance 

 Survey, on the scale of one inch to a mile, he began to map the 

 geological structure of that part of the country. This labour was 

 carried on with his own hands and at his own charges. As it 

 advanced, he was led to perceive that it might possess great public 

 importance in regard to the development of the mineral resources of 

 the kingdom. An accurate delineation of the courses of the mineral 

 veins, coal-seams, and other useful substances contained among the 

 rocks beneath the surface, and of the bearings of the faults that 

 dislocate and shift them, could hardly fail to prove of much practical 

 value as well as of scientific interest. After he had made some 

 progress with his self-imposed task, De la Beche was induced to 

 apply to the Government of the day for recognition and assistance. 

 The Ordnance Survey, indeed, under the enlightened supervision of 

 Colonel Colby, had already encouraged the surveyors of its staff to 

 keep a record of their observations respecting the relations between 

 variations in the topography of the land and changes in the characters 

 of the rocks underneath. In this manner the geology of the distiict 

 around Ludlow, together with that of the Forest of Dean and the 

 central parts of Herefordshire, had been with more or less precision 

 traced upon the Ordnance sheets.^ De la Beche represented to the 

 authorities that the work on which he was engaged would be much 

 more efficiently carried out if it were conjoined with that of the 

 general trigonometrical survey of the whole country, which was then 

 in progress. His views wex'e eventually approved of, and in the 

 year 1832 he was appointed by the Board of Ordnance to affix 

 geological colours to the maps of Devonshire, with portions of 

 Somerset, Dorset, and Cornwall. By the Spring of 1834: he was 

 able to publish four slieets of the geological map of the county of 

 Devon, whereon the general geological structure was depicted with 

 a minuteness and beauty of execution such as had not before been 

 equalled. Three additional sheets of the Ordnance Survey were 

 completed by the end of that year, while another was nearly 

 finished. - 



This rapid progress and the obvious advantages to be derived 

 from the maps led to a more definite recognition of De la Beche's 



1 Proc. Geol. Soc, vol. i, p. 447. 



2 Op. cit., Yol. ii, p. 154. 



