660 JOSEPH PRESTWICH. 



Iii his earlier papers on Eocence formations lie dealt with the age and 

 relations of the London Clay and Bagshot Beds. He proved the con- 

 nection of the London Clay and Bognor Beds, and showed that they 

 were older than the clays and sands of Bracklesham and the clays of 

 Barton. He subdivided the Bagshot Beds, and correlated with them 

 certain strata in Hampshire and the Isle of Wight. Subsequent 

 researches by Mr. Starkie Gardner, Mr. Monckton, and Mr. Herries, 

 have thrown doubt on the correlation of the Upper Bagshot Sands of 

 Surrey with those of Hampshire (the Headon Hill Sands); and in a 

 later work ] Prestwich agreed that the Upper Bagshot Sands of the 

 London area might be partly or wholly of Bracklesham age. Beady 

 at all times to accept corrections when assured of their accuracy, he 

 was also not unwilling to admit changes in classification when the 

 alteration was for the general convenience. Thus he adopted the term 

 Oligocene for strata previously grouped as Upper Eocene. He did not, 

 however, agree with Mr. Whitaker in his proposal to form a separate 

 division, termed the Oldhaven Beds, from strata in part grouped by 

 Prestwich with the basement bed of the London Clay, and in part with 

 the Woolwich and Beading Series. 



Continuing his researches Prestwich described in full detail the 

 strata between the London clay and chalk, giving the names "Thanet 

 Sands" and "Woolwich and Beading Series" to strata previously 

 grouped together as the "Plastic Clay Formation." Beferring to the 

 important series of Eocene memoirs, which he had completed in 1854, 

 Edward Forbes remarked, "These remarkable essays embody the 

 results of many years' careful observation, and are unexcelled for 

 completeness, minuteness of detail, and excellence of generalization.'" 



A popular account of the Eocene strata and of the superficial depos- 

 its that occur in the neighborhood of London was given by Prestwich 

 in 1854 and 1856, in the course of three lectures on the geology of 

 Clapham, and these were published a year later under the title of 

 The Ground Beneath Us. Clearly and pleasantly written, this little 

 work was well calculated to arouse the interest of the reader, and at 

 the time of its publication it was one of the best introductions to 

 geology which it was possible to place in the hands of a beginner. 



While Prestwich gave his attention in the main to pure science, he 

 did not neglect the important applications of knowledge. By his pub- 

 lication in 1851 of A Geological Inquiry Bespecting the Water bearing 

 Strata of the Country around London he came to be recognized as 

 the leading geological authority on the subject; and in 1867 he was 

 appointed a member of the Boyal Commission on Metropolitan Water 

 Supply. 



He was elected a fellow of the Boyal Society in 1853, and vice- 

 president in 1870; in that year also he became president of the Geo- 

 logical Society. In his second address to that society in 1872 he gave 



'Geology, Vol. II, page 364. 



2 Address to Geological Society, 1854. 



