470 SOME NEW BOOKS [jtjne 



fault, which has "the enormous downthrow of at least 9000 feet to the south," 

 have been carefully worked out, and are clearly shown in the geological map 

 and sections. 



The Surveyors have conscientiously compared the notes and descriptions by 

 earlier observers with the sections and other features which they themselves have 

 studied and illustrated with precision. Being well-trained geologists they have 

 drawn valid conclusions ; for the most part confirming and enlarging those 

 arrived at by A. G. Bain and other early observers. Mr. Saunders's Bibliography 

 is a great help in referring to what has been published since 1841 (Clarke), 

 1844 (Darwin), 1845 (Bain), etc. 



Summaries of local work by Messrs. Rogers and Schwarz are given in the 

 First Report. A good map, with sections, illustrates the distribution of the 

 dolerites in the Nieuweld Mountains, as described by Mr. Schwarz in his account 

 of the district of Beaufort- West. There is also an elaborate sketch-plan, by Dr. 

 Corstorphine, of the Cango Cave in the dolomite, near Oudtshoorn, south of 

 the Zwartebergen. 



In the Second Report a very welcome geological map of the district already 

 surveyed (as defined above) is given, on a scale of 1:800000 (1 inch to 12*62 

 English statute miles), in Plate T. Five long and very instructive geological 

 sections, from north to south, on a scale of 1 inch to 1*878 miles, or 800 Cape 

 roods, are given in Plate II. In this Report Mr. Rogers gives an account of 

 the Survey of the Stellenbosch district, and Mr. Schwarz that of the Robertson 

 and Swellendam Divisions ; and both together draw up a summary of the work 

 done during 1897 in the area between the Langebergen and the Karoo. Here 

 occur the Table-Mountain Sandstone, the Bokkeveldt and Witterberg Beds, the 

 Dwyka Series, and the Ecca Beds ; more especially illustrated in Sections 3, 4, 

 and 5 of Plate II. The Dwyka Series of shales and conglomerates, lying con- 

 formably on the Witterberg quartzite, in particular is described, Mr. E. J. 

 Dunn's careful notes being largely incorporated. The glacialised condition of 

 the materials of the conglomerate is accepted ; these are pebbles and fragments 

 of " several varieties of granite, . . . several kinds of more basic igneous rock, 

 sandstones, quartzites, argillaceous and calcareous rocks, and vein -quartz. 

 Under the microscope the matrix is seen to consist of "minute fragments of 

 anisotropic substances, . . . with quartz, felspar, . . . garnet, epidote, augite, 

 . . . white and brown mica, sphene, magnitite, . . . calcite, as pebbles and 

 grains, and as a secondary product." Included in the Dwyka Series are some 

 peculiar superincumbent shales and sandstones, succeeded by black graphitic 

 and pyritous shales ; above these are the conformable Ecca sandstones and 

 shales, containing plant-remains, and lying in folds parallel with the mountains, 

 Zwartebergen, etc., on the south. To the north the great Karoo Series is 

 present, and, together with the Eastern Province, will be reached by the Survey 

 in due course. 



At pages 37-43 Dr. Corstorphine supplies an interesting and philosophical 

 review of the geological history of the successive formations constituting the 

 country which the Geological Survey as yet has been able to determine and 

 describe. T. R, Jones. 



SCIENCE FOR THE YOUNG. 



Early Chapters in Science. By Mrs. W. Awdrey. Edited by W. F. 

 Barrett. 8vo, pp. xviii. + 348, with figs. London : John Murray, 

 1899. Price 6s. 



The object of this book, writes Prof. Barrett, is to provide young people, 

 especially the junior classes in schools, with an introduction to the two 

 great' divisions of science — Biological and Experimental — to the World of 

 Life and the World of Experience — and, in a word, to cover the ground of 

 Mr. Paul Bert's " First Year of Scientific Knowledge " in a more attractive 



