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SECTION 16. GEOLOGY AND MINING, 



WEST GALLERY, ROOM L and M. 



I. GEOLOGY. 



1. SPECIAL COLLECTIONS. GEOLOGICAL SOCIETY OF LONDON. 

 a. GEOLOGICAL INSTRUMENTS AND APPARATUS. 



3247. Apparatus, &c. employed in Sir James Hall's cele- 

 brated experiments. The Geological Society of London. 



A series of specimens, with the instruments employed in their preparation, 

 illustrating the remarkable experiments carried on by Sir James Hall, Bart., 

 between the years 1787 and 1805, to confirm some of the positions taken up 

 by Dr. James Button in his celebrated " Theory of the Earth." The series 

 consists of the following 



(1.) A selection of whinstone and lava rocks which have been fused and 

 allowed to cool under various conditions. These are the products of the 

 earliest experiments, which were carried on in ordinary clay crucibles. 



(2.) Porcelain tubes employed in the first attempts to submit carbonate of 

 lime and other substances to a high temperature under pressure. 



(4.) " Gun-barrels," employed in the final and successful experiments for 

 the same purpose ; with the cylinders of rock operated upon. 



(The collection of apparatus and specimens from which the above are selected 

 was presented to the Geological Society of London by Captain Basil Hall, 

 R.N., at his father's death.) 



3248. Geological Model of the South-east of England 

 and part of Prance, including the Weald and the Bas Bou- 



lonnais. Founded upon the maps of the Ordnance, Admiralty, 

 and Geological Surveys. Scale, 1 inch to 4 miles. 



W. Topley, F.G.S., and J. B. Jordan. 



This model illustrates the close connexion which exists between the geo- 

 logical structure of a district and the " form of the ground." The chief hill 

 ranges and the broad longitudinal valleys correspond with the outcrops of 

 hard or soft rocks ; the transverse valleys, in which the main rivers run, cut 

 across all the rocks alike. 



3249. Agricultural Map of Kent. Scale, 1 inch to 4 miles. 



William Topley, F.G.S. 



This map is founded upon the published maps of the Geological Survey, 

 additions and modifications of colouring for agricultural purposes being made 

 by the author. Stiff and retentive soils are coloured dark tints, grey, purple, 

 and brown ; light and absorbent soils, yellow or light green ; calcareous and 

 absorbent soils, blue. 



