51 



159. Geological model of a volcanic district, by Reyer. 

 Size 7^ in. by 7J in. Scale f in. to the mile. 



Lent by the, Geological Laboratory, Royal College of 

 1887. Science. 



In three colours, two for sedimentary rocks, and one for 

 eruptive. The two sedimentary rocks are in loose pieces, which 

 may be removed so as to show the position of the eruptive rocks 

 below ground. 



160. Geological model of the volcanic district of 

 Predazzo, by Reyer. Size 9^- in. by 9^- in. Scale 2| in. 

 to the mile 3^0- 



Lent by the Geological Laboratory, Royal College of 

 1887. Science. 



Shows 10 colours for Wengener Kalk, Muschel Kalk, Sand and 

 loose stones, Quartz-Porphyry, Monzonite, Syenite, Granite, Dark 

 coloured Porphyry, Elseolite-Porphyry, and Orthoclase-Porphyry. 



161. Model showing stratification in rocks. 



Under a glass shade. Size 18 in. by 9 in. by 10 in. 

 high. 



E. 315. 1877. Published by C. Delagrave, Paris. 



Model of a quarry showing thin oblique beds in the quarry 

 face, without any conspicuous joints. 



162. Set of four models of part of the Jura Mountains- 

 chain of Reculet. By L. I. Bardin and Commandant 

 Peigne, scale 4-^3-00-. Size 2 ft. 8 in. by 1 ft. 8 in., re- 

 presenting an area of 40 square leagues. Under glass 

 shades. 



E. 310 and 316 to 318. 1877. 



Published by C. Delagrave, Paris* 



This set is designed to show the method of preparing geolo- 

 gical models by the aid of maps. 



The first is constructed by taking a map on which the 

 contour lines are marked at intervals of 10 metres or S3 feet. 

 Sheets of cardboard of uniform thickness are then cut out so 

 that their outline corresponds with the contour lines. A flat 

 surface is then taken, and the cardboards representing the 

 lowest contour, say of 10 metres above the lowest point in 

 the district, are glued on in their proper places. On the surface 

 of these the cardboards representing the next higher contours 

 of 20 metres, are glued and so on, till the highest contoured 

 cardboard has all the lower contours beneath it. The model 

 then shows the contour lines by the edges of the several sheets 

 of cardboard, and the higher parts are raised above the lower 



