406 Notices respecting New Booh. 



A detailed account of this calculation is about to be published 

 in the ' Journal of the Physical Society of St. Petersburg/ 

 I am. Gentlemen, 



Yours most respectfully, 



A. Stoletow, 



Professor of Physics. 



XL VII. Notices respecting New Books. 



Geological Survey of England and Wales. Guide to the Geology of 

 - London and the Neighbourhood. By William Whitaker, B.A., 

 F.G.S. 8vo, pp. 72. London : Longmans and Co. and E. 

 . Stanford. 1875. 



npHIS is an explanation of the Geological-Survey Map of London 

 -r- and its environs, and of the Geological Model of London in the 

 Museum of Practical Geology in Jermyn Street, London. The 

 map was one of the special geological maps, instituted by the late 

 Director-General Sir R. I. Murchison, showing the superficial gravels, 

 sands, loams, peat, &c, which are'usually ignored in common geolo- 

 gical maps, but are really of great importance to the agriculturist, 

 horticulturist, and house-occupier, and to the constructors of 

 houses and other buildings, docks, canals, sewers, and surface-drains. 

 The model — one of the finest and most accurate ever made — has a 

 horizontal scale of 6 inches to the mile ; and, having a length of about 

 15 miles E. and W. and a breadth of about 11 miles N. and S., re- 

 presents an area in and around London of about 165 square miles. 

 This is divided into nine four- sided masses of unequal size, bounded 

 by lines known to afford sections from wells and borings. Five of 

 these portions can be raised by machinery, worked by a handle, so as 

 to bring up and show the sections along the inner sides of each. The 

 vertical scale was necessarily exaggerated, and is about 4-4 times 

 as large as the horizontal ; but this does not appear excessive. This 

 model was successfully made under the superintendence of Messrs. 

 "Whitaker, Jordan, and Brion, and placed in the Museum in 1873. 

 A description of the model and of its construction, and of the seve- 

 ral lines of section traversing it, is given in full at pages 4-13. 



The body of this valuable memoir is occupied with the description 

 of the several geological formations known to constitute the soil, sub- 

 soil, substrata, and foundations of the London area. This great series 

 of earthy and stony materials is briefly, but pointedly, described 

 from the lowest known strata upwards ; and very much infor- 

 mation is given as to the water-supply and the local features 

 and scenery, dependent on the structure (pages 14-68). Detailed 

 descriptions of the deposits, sections, and fossils have been already 

 published in the larger and still richer memoir on the whole of 

 the London District, by Mr. Whitaker and his colleagues, in vol.iv. 

 of the ' Memoirs of the Geological Survey,' 1872. 



