Revieus — Life of Sir Joseph Predwich. 379 



the rivers were formerly vastly larger than they now are ; that, in 

 virtue of their size, width, and transporting power, they were able 

 to carry downward and spread out over their flood-plains the widely 

 distributed sheets of course shingle now remaining ; while from 

 time to time they rose in floods of extraordinary magnitude that 

 deposited the fine silt, containing land-shells, which is now to 

 be seen covering all the different gravel - beds. Considerable 

 differences of opinion still exist, however, regarding some of these 

 deductions. Other observers, as remarked above, have been unable 

 to perceive any satisfactory evidence that the rivers were generally 

 more swollen than they are at present, though at exceptional 

 periods of melting snow they may have surpassed in volume any 

 floods chronicled in their valleys during historic times. But 

 Prestwich detected the traces of another transporting agent than 

 that of mere unaided river-water. In the presence of large unworn 

 blocks among the ancient gravels, together with much sharp angular 

 detritus, he recognized the operation of river-ice. Thus, all over 

 the south-east of England, wliere the climate is now so mild, he 

 traced indications that in old times the rivers flowing on the platform 

 of the higher gravels were frozen over ; that ice forming along their 

 margins or over their bottoms lifted and carried along the shingle 

 and boulders lying there, and that when these Arctic conditions 

 prevailed, man had already appeared, fishing in tlie rivers, or 

 tracking the mammoth, the bison, and various extinct forms of deer 

 through the surrounding forests and prairies." 



" Among Prestwich's contributions to the history of the latest 

 geological changes that have affected the South of England and 

 North of France, his numerous papers on the so - called Eaised 

 Beaches of this region deserve recognition." (p. 415.) 



" One of the most useful services rendered by Sir Joseph Prestwich 

 to the cause of his own science was the active sliare he took in the 

 practical applications of geology. His labours in this department 

 were manifested in two different directions. In the first place, he, 

 more than other geologists of his day, insisted on the necessity of 

 a knowledge of geological structure in dealing with the question 

 of water-supply. From his earl3' communication to the Institute 

 of British Architects down to his pamphlet on the Oxford Water- 

 Supply, an interval of thirty-five years elapsed, during which he 

 came to be regarded as the leading authority on this subject in 

 England, and his co-operation doubtless added much to the value of 

 the Report of the Royal Commission on Water-Supply issued in 1869. 

 It is to be regretted that the maps prepared by him for this Report 

 were never published. In the second place, his early devotion to 

 the coalfield of Coalbrookdale gave him a knowledge of our Car- 

 boniferous system, and an interest in its development, which he 

 turned to good use in later years, when he acted as a member of 

 the Royal Commission on Coal. Not the least valuable part of that 

 important and voluminous work was supplied by him in his papers 

 on the quantity of unwrought coal in the coalfields of Somerset, and 

 on the probability of finding coal under the newer formations of the 



