xxir. 



THE AGRICULTURAL GEOLOGY OF HERTFORDSHIRE. 

 By J. YiNCEXT Elsdex, B.Sc. (Lond.), F.C.S. 



Read at St. Albans, I9th December, 1882. 



PLATES II AND III. 



I. Intkodtjctory and General. 



Haying been requested to read another paper before the Society, 

 I cannot think of a topic more likely to command general interest, 

 in a district so essentially agricultural, than the connection between 

 the geological and agricultural features of our county, and the 

 natural causes which have influenced the chief industries carried 

 on around us. For, besides the special interest which attaches 

 itself to this subject, there is always a general satisfaction in dis- 

 cussing the practical utility of a science, which, like geology, is 

 too often looked upon rather as a harmless recreation than as a 

 means of developing the utmost resources of the soil, and of dis- 

 covering those mineral products upon which so much of the wealth 

 and power of a nation depends. 



It needs but a careful examination of any district to show that 

 its agricultural features are influenced, to a large extent, by the 

 geological nature of the rocks which form its surface ; for upon this 

 will depend not only the natural fertility of the soil and its capa- 

 bilities for improvement, but also the expense of working it, and 

 the care and attention necessary to prevent its deterioration. Upon 

 geological structure, also, will depend, to a certain extent, climate, 

 water-supply, and necessity for di-aining, as well as the possibility 

 of obtaining materials for improving the condition of the land by 

 artificial admixture of soils. 



It is undoubtedly the tendency of improved systems of agriculture 

 to overcome natural obstacles to the growth of certain crops in soils 

 which are unsuited to them, and thus to destroy, to a certain 

 extent, the diversity of character which formerly existed in a more 

 marked degree between the agricultural features of different geo- 

 logical formations. For instance, the agricultural features of the 

 chalk districts of England are by no means so marked, now that 

 they have been invaded by the plough, as they were when in open 

 downs and sheep-pastures only. 



But even in these cases the improvement is only artificial, and 

 the natural conditions would soon reappear if constant attention 

 were not paid to the maintenance of the soil in an improved state. 

 To the ordinary observer the appearance of a naturally fertile soil, 

 and of a soil rendered artificially productive, may be very much 

 the same ; but to the farmer the difference is extreme ; for, while 

 the former is worked with ease, the latter can only be made to 

 yield good results by endless trouble and expense. 



Hence the farmer derives assistance from a knowledge of geology 

 in nearly every branch of agriculture. Not only can he, by its 



VOL. II. — part IV. 10 



