Vol. 50.] ADDITIONS TO THE LIBRARY. _ 245 



Hague, A. See United States. 



Hahn, E. Zur wirtschaftlichen Stellung des Negers. (F. Fr. von 

 Richthofen, Festschrift, 371.) 8vo. Berlin, 1893. Purchased. 



Barker, Alfred. Notes on North of England Rocks. I.-II. 8vo. 

 Huddersfield, 1889 & 1890. 



Notes on the Physics of Metamorphism. 8vo. London, 

 On " Eyes " of Pyrites and other Minerals in Slate. 8vo. 



1889. 



London, 1889. 



— . On Local Thickening of Dykes and Beds by Folding. 8vo. 

 London, 1889. 



— . Penological Notes on some Boulders from the Boulder- 



Clays of East Yorkshire. 8vo. Halifax, 1889. 

 -. Notes on a Collection of Rocks from the Tonga Islands. 



8vo. London, 1891. 

 — . On various Crystalline Rocks. 8vo. London, 1891. 



— . Petrological Notes on some of the larger Boulders of the 

 Beach South of Flamborough Head. 8vo. Halifax, 1891. 



The Ancient Lavas of the English Lake District. 8vo. 



Huddersfield, 1891. 



— . Thermometamorphism in Igneous Rocks. 8vo. Minnea- 

 polis, 1891. 



— . On Porphyritic Quartz in Basic Igneous Rocks. 8vo. 

 London, 1892. 



Physical Geology in the Basin of the Colorado. 8vo. 



London, 1892. 

 — . Some North-Country Quartzites. 8vo. Huddersfield, 



1892. 



The Lamprophyres of the North of England. 8vo. London, 



1892. 



— . Berthelot's Principle applied to Magmatic Concentration. 

 8vo. London, 1893. 



Extinction-Angles in Cleavage Flakes. 8vo. London, 



1893. 



— . On the Migration of Material during the Metamorphism of 

 Rock-masses. 8vo. Chicago, 1893. 



Norwegian Boulders in Holderness. 8vo. Huddersfield, 



1893. 



