Dr. Cyrus Adler, 



Librarian U. S. Nat. Museum. 



VOL. XXX. 



MAECH, 1908. 



Established by BENJAMIN SILLIMAN in 1818. 



THE 



AMERICAN 



JOURNAL OF SCIENCE. 



Editor: EDWABD S. DANA. 



ASSOCIATE EDITORS 



Professors GEOEGE L. GOODALE, JOHN TEOWBEIDGE, 

 W. G. FAELOW and WM. M. DAVIS, op Cambridge, 



Professors ADDISON E. YEEEILL, HOEAOE L. WELLS, 

 L. V. PIESSON and H. E. GEEGOEY, of New Haven, 



Professor GEOEGE E. BAEKEE, of Philadelphia, 

 Professor HENEY S. WILLIAMS, of Ithaca, 

 Professor JOSEPH S. AMES, of Baltimore, 

 Mr. J. S. DILLEE, of Washington. 



FOURTH SERIES 



VOL. XXY— [WHOLE NUMBER, CLXXY.] 

 No. 147— MARCH, 1908. 



NEW HAYEN, CONNECTICUT. 



19 08 



THE TTJTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. 



Published monthly. Six dollars per year, in advance. $6.40 to countries in the 

 i Union ; $6.25 to Canada. Eemittances should be made either by money orders, 

 registered letters, or bank checks (preferably on New York banks). 



