Davis — Framework of the Earth. 237 



But they will find more ; for de Margerie has used his 

 marvellous bibliographic knowledge to enrich the trans- 

 lation by adding a vast fund of references as well as a 

 large number of illustrations not contained in the original 

 work ; all these additions being pointed out with scrupu- 

 lous conscientiousness, the new references enclosed in 

 brackets, and the new illustrations marked with an aster- 

 isk in the index volume, where all maps and figures are 

 conveniently grouped geographically in a separate list. 

 The French translation thus serves even better than the 

 German original as an introduction to the structural geol- 

 ogy of the world, with especial reference to such problems 

 as are most directly related to the study of earth-crust 

 elements. The use of the translation is moreover facili- 

 tated by an excellent index, representing an enormous 

 amount of fatiguing work; it occupies 176 pages of the 

 supplementary partial volume, and contains upwards of 

 8,000 headings with over 50,000 page references. The 

 French version is, therefore, destined to become the 

 working basis of the future investigations, which it is 

 to be hoped will be the main and great outcome of Suess 's 

 studies. 



As such, "La Face de la Terre" may be used to great 

 profit by advanced students who set out, under the guid- 

 ance of their professor, upon a winter's indoor campaign 

 to acquire mental possession of a selected crustal ele- 

 ment; not alone with the object of learning its structure 

 as described by Suess, but also with the intention of 

 testing the accuracy of his descriptions and generaliza- 

 tions by confronting them with the new material to which 

 de Margerie 's added references lead. Such a campaign 

 must, to be successful, be conducted in the neighborhood 

 of a good depot of munitions, where the geological litera- 

 ture of the world is accessible. In case the campaign can- 

 not be undertaken because the near-by depot — or library 

 — is deficient in material, let the librarian be urged to 

 complete his collection by ordering as soon as possible 

 all the works to which reference is made in the original 

 and the added footnotes of "La Face de la Terre." 

 Any library thus equipped will be a geological strong- 

 hold indeed. 



Yet even with a well-stocked library at hand, how 

 difficult is the studious reading of Suess 's work, in what- 

 ever language it is attempted ! Its pages abound in place 



