Geology and Natural History. 425 



Jacob et J. Offner. Pp. vi, 112, plates iv + ix, maps Hi. — In 

 the preface attention is called to the great importance of com- 

 plete investigation of the water resources of every region in order 

 that the factors may be understood which control the run-off 

 throngiiout the year. In the Alps not onlj^ do the lakes act as 

 storage reservoirs but the glaciers also. The latter discharge 

 their stores especially during the summer and also more 

 abundantly during warm cycles of years, at the present time 

 the glaciers being in general retreat. They thus act as 

 storage reservoirs in ways different from lakes though equally 

 important. Investigations upon glaciers have, however, been 

 hindered by the lack of knowledge regarding their depth, 

 the third dimension which is so readily ascertained for measuring 

 the cross-section and run-off of rivers and lakes. The first part 

 of the present work gives the details of the methods devised and 

 successfully used for boring to the bottom of glaciers and thus 

 determining their cross-section. The second part gives detailed 

 studies and maps of the massif of the Grandes Rousses and its 

 glaciers, the region where these methods were pursued. There is 

 thus given here a very complete investigation of a group of 

 glaciers considered as reservoirs of water stored in the solid form, 

 a unique hydrologic investigation whose methods will doubtless 

 be extended to other regions. j. B. 



15. JBeitrdge zur Geolugie der Samoainseln ; von I. Fribd- 

 LANDER. Abh. k. Bayer. Akad. Wiss., II Kl., xxiv, Abt. Ill, pp. 

 509-541. Based on visits to all the main islands of the Samoa 

 group, the writer gives a general sketch of their geological charac- 

 ter and considerable detail regarding the most striking features of 

 each. Since the islands are purely volcanic, it mostly concerns the 

 arrangement and relative' age of the new and old craters, lava 

 masses and tuffs. The writer has visited also Hawaii and Fiji 

 and, agreeing with Woolnough that the latter consists of vol- 

 canics piled on the remnants of a continental platform, he sug- 

 gests that the volcanic masses forming the other two, if we 

 consider them to rise wholly from the ocean floor, are of enor- 

 mous dimensions, entirely beyond anything known on the land. 

 In Hawaii, taking into account the small volcanic islands and 

 coral reefs, the ridge stretches some 1500 miles with a maximum 

 height of 30,000 feet. In Samoa the ridge is 300 miles long and 

 20,000 feet high. This suggests that these, like Fiji, are built 

 on a submerged continental platform. Two maps and a number 

 of excellent plates of photographs accompany the article. 



L. V. p. 



16. Artificial Lava Flow audits Spherulitie Crystallization. — 

 Under this title in the August number of this Journal of the 

 current year (p. 97), the writer described an accidental flow of 

 glass, and the spherulites which formed in it. In the article it 

 was stated that the conditions obtaining, and the relative positions 

 of the specimens described, were unknown. Since then the writer 

 has received a letter from Mr. R. L. Frink of Columbus, Ohio, a 



Am. Jour. Sci.— Fourth Series, Vol. XXX, No. 180.— December, 1910. 



38 



