THE LEWIS BROOKS MUSEUM. 11 



The following enumeration includes all the more im- 

 portant of the phenomena illustrated : 



(1.) Columnar structure, shown in Basalt from various 

 localities ; (2.) Alteration of sedimentary rocks by igneous 

 dykes ; (3.) Veins of segregation, veins of aggregation and 

 infiltration, &c; (4.) Jointed structure : (5.) Slaty cleavage; 

 (6 ) Polished surfaces or slicken sides; (7.) Contorted and 

 folded laminae ; (8.) Concretions. The series of concretions 

 is very lull, the material being mainly clay, limestone and 

 pyrite ; (9.) Glacial markings ; (10.) Ripple marks and rain 

 drop impressions; (11.) Flexible sandstone; (12.) Geodes, 

 empty, nucleated and lined with crystals ; (12.) Cone in 

 cone, dendrites, &c, the latter very numerous and hand- 

 some; (14.) Volcanic bombs , scoria, amydaloids, &c; (15.) 

 Stalactites, stalagmites, &c; (16.) Meteoric stones from the 

 United States and Mexico, and with these fac similes of 20 

 celebrated meteorites. 



This series is completed by an important series of geo- 

 logical models and maps. («.) A relief map (5 feet square) 

 of the region of extinct volcanoes in Auvergne, France, show- 

 ing fully the grand succession of changes which this region 

 has undergone, (b.) A series of six relief maps of volcanic 

 mountains and islands, colored geologically. They repre- 

 sent Mt. Vesuvius, Mt. Etna, Mt. Blanc, and the Islands 

 of Teneriffe, Palma and Bourbon, (c.) A number of maps, 

 views and charts of noted geological sites or phenomena, in 

 various parts of the world, accompany the collection. 



Besides the above relief maps, the collection possesses a 

 splendid relief map (6 feet square) of the Grand Canon of 

 the Colorado river, and the cliffs of Southern Utah, pre- 

 pared from data obtained in the survey of the Rocky Moun- 

 tain region under Major Powell. Also two relief maps of 

 the Henry Mountains, three and a half feet by five, present- 

 ed by the Hon. John Goode. The first of these shows the 

 relief features of the country before erosion, and the second 

 the present topography produced by erosion. 



