i866-i86; AGRONOMICAL MAP OF BRITAIN 293 



years the Geological Survey had been carefully dis- 

 tinguishing and mapping the various superficial 

 deposits which, in the earlier days of the work, it had 

 not been thought necessary to discriminate. Apart 

 from their great scientific interest, maps of the surface 

 geology had innumerable advantages of a practical kind. 

 They gave information as to the nature and distribu- 

 tion of soils, and were thus of value for agricultural 

 purposes. They were of essential service in the con- 

 struction of reservoirs, and generally in questions of 

 water-supply. They were of great utility in the laying 

 out of roads and railways ; and they could be made 

 to furnish valuable evidence in relation to drainage 

 and sanitary matters. The importance of such maps 

 being recognised by Government, it was desired to 

 afford greater facilities for their production. It was 

 now arranged that the practice of mapping the super- 

 ficial deposits simultaneously with the solid rocks 

 underneath them, which had been introduced into the 

 Survey some years previously, should be continued 

 over all the unsurveyed districts, and that, as soon as 

 surveyors could be detached for the purpose, the 

 tracts already surveyed where the surface-formations 

 had not been separated should be re-traversed for the 

 purpose of inserting them. By this means a general 

 agronomical map of the whole country would be pro- 

 vided, which would be of much service for farming 

 purposes, land -valuation, drainage, water-supply, and 

 many other practical affairs of life. These designs 

 have since that time been steadily kept in view, and a 

 large part of the country has now been completed. 



The changes in the Survey staff could not come 

 into operation until the beginning of the financial year, 

 that is, the ist April 1867. Steps had been taken 



