172 Reviews — Professor Charles Barrois — 



of French geology. Towards the close of his life, iu 1849, Constant 

 Prevost let it be known that he had brought to light from his 

 notebooks a work which had lain dormant since 1821 on the 

 geological structure of the cliffs of jS'orraandy.^ A desire to make 

 it less imperfect, the hope of embracing in its scope the whole 

 coast of France, had allowed him to defer its publication. Before 

 putting the final touches to it he wished to make an appeal to young- 

 geologists who had a long future before them, as well as to those 

 who from their position and residence by the coast would be able to 

 make prolonged local researches. But when he died in 1856 his 

 collaborators had not yet appeared, and his descriptions of the 

 Normandy cliffs remained for ever in his notebooks, whilst his 

 geological theories forged ahead and the Geological Society of France, 

 founded by him, developed and flourished. And it is only in our 

 days, after eighty-seven years, that the dream of one of our masters 

 is at last realized in the work that bears the title *' The Zones of 

 the White Chalk of the English Coast," a work which has for author 

 A. W. Eowe and for collaborator C. 1). Sherborn. 



The fact is it is very difficult to study a cliff thoroughl3\ A cliff 

 shows too much, all at once. It shows so much that it always 

 appears as if one had missed something, and one is always condemned 

 to a sense of incompleteness, whatever care may be taken to rivet the 

 attention, to brace up soft muscles for the climb, or whatever 

 dexteritj' one may show with the chisel and the pencil. 



The English Chalk has, without doubt, been the object of work of 

 high value on the part of members of the Geological Survey, as seen 

 in the works of AVhitaker and Strahan and the admirable memoir by 

 Jukes-Browne on the Cretaceous rocks ; but the best-made maps, the 

 most careful geological surveys, are always at the mercy of a trench, 

 or of a new quarry bringing to light contacts previously invisible. 

 The observer who describes a cliff is protected from these risks; if 

 he allows any fact to pass unnoticed he has only himself to blame ; 

 he has not been competent to take the necessary trouble. 



For my own part I never stand before a cliff that I have previously 

 studied without making some new observation or noticing something 

 which had formerlj^ escaped me. But to-day the harvesters have 

 passed over the English coast in Rowe and Sherborn, and the work 

 for tlie gleaner who follows their footsteps will be but small. 



Let us rapidly examine the characters of the Chalk cliffs in the 

 different counties studied. 



ire?it. 

 Twelve years of observation are condensed into the fine sections of 

 the Kentish cliffs ; anyone with the descriptions and sections in his 

 hand can follow the coast and recognize without hesitation the 

 succession of the eight zones of the Chalk and their limitations at 

 an)' point. The author has brought precision and exactness where 



' Constant Prevost, "Description geologique du littoral de la France": C.E. 

 Acad. Sci. Paris, vol. xxix, November 26tli, 1849, pp. 615-622. The work of 

 C. Prevost, " Sur les falaises de la Manche," had been seen by Cuvier and 

 Brongniart, who reported upon it to the Academy. 



