312 Notices of Memoirs — The Geological Survey. 



country include the central mountains of Sutherland and Eoss, 

 with most of Inverness-shire, the western parts of Argyllshire, and 

 most of the Western Isles. 



When the one-inch map of England was completed, most of the 

 staff was detailed for the purpose of mapping the superficial deposits 

 in the southern half of the kingdom, and thus providing materials 

 for a complete agronomic map of the whole of Britain. An oppor- 

 tunity has at the same time been afforded to revise the published 

 maps and bring them up to date. The nature and extent of this 

 revision will be more particularly noticed in subsequent pages; 

 When the one-inch map of Ireland was finished the staff was 

 reduced, partly by transference to Scotland and partly by retire- 

 ment, only such a number of ofScers being retained as might suffice 

 for the necessary revisions which the progress of time requires. 

 To these revisions also fuller reference will be made in the sequel. 



II. The Woek of the Geological Survey. 



The combined scientific and j^ractical objects which De la Beche 

 set before himself as his great aim at the first institution of the 

 Geological Survey, have ever since been kept steadily in view. To 

 this day the development of the mineral fields of the country by means 

 of accurate maps, the collection of data for the guidance of those in 

 search of water-supply, the accumulation of information required for 

 the purposes of agriculture, engineering, road-making, architecture — 

 these and many other applications of geology to the arts, manu- 

 factures, and practical affairs of our social life continue to form a 

 large part of the work of the Survey. But, as De la Beche and his 

 early associates clearly recognized from the beginning, all such 

 utilitarian uses of geology must be based on a thoroughly sj'stematic 

 examination of the geological structure of the country. So closely 

 are pure science and industrial progress linked together, that at any 

 moment what might be supposed to be a matter of merely theoretical 

 import may be discovered to have a high practical significance and 

 value. Hence the Geological Survey has been conducted as a strictly 

 scientific investigation, and has thus been able to advance the interests 

 of geological science. The geological structure of the British Isles 

 has been traced out in greater detail than was before attempted in 

 any country, and numerous additions have thereby been made to the 

 general body of geological knowledge. 



1. Field Woek.^ — The first and most important duty of the 

 Survey is to map in detail the geological structure of the country. 

 When this task was first undertaken by De la Beche the Ordnance 

 Survey maps on the scale of one inch to a mile (es-iso) which had 

 then been published for some of the southern counties of England, 

 and which he used as the basis of his work, were imperfect and 

 incorrect in their topography. They were among the first under- 

 takings of the Ordnance Survey, before methods of surveying had 



1 Some portions of the following account of the work of the Geological Survey- 

 are taken from a paper communic'ated by the Director- General to the Federated 

 Institution of Mining Engineers. See the'ir Transactions, yoI. v (1893), p. 142. 



