SCIENCE 



Editorial Committee : S. Newcomb, Mathematics ; E. S. Woodward, Mechanics ; E. C. Pickerino, 



Astronomy ; T. C. Mendenhall, Physios ; E. H. Thdrston, Engineering ; Ira Eemsen, Chemistry ; 



Joseph Le Conte, Geology ; W. M. Davis, Physiography ; Henry F. Osborn, Paleontology ; 



W. K. Brooks, C. Hart Merriam, Zoology ; S. H. Scudder, Entomology ; C. E. Bessey, 



N. L. Britton, Botany ; C. S. Minot, Embryology, Histology ; H. P. BOWDITCH, 



Physiology ; J. S. Billings, Hygiene ; William H. Welch, Pathology ; 



J. McKeen Oattell, Psychology ; J. W. Powell, Anthropology. 



Friday, June 29, 1900. 



CONTENTS: 



The American Association for the Advancement of 

 Science : — 



Rhythms and Geologic Time: G. K. Gilbert.... 1001 

 The Eighth Group of the Periodic System and 

 some of its Prolleins : Professor Jas. Lewis 

 Howe 1012 



The Soyal Society of Canada : Dr. H. M. Ami 1020 



Scientific Books : — 



Welton on the Logical Bases of Education : Pro- 

 fessor Paul H. Hanus. Rice on the Tlieory 

 and Practice of Interpolation : Professor C. L. 

 Doolittle. Books Received 1024 



Scientific Journals and Articles 1027 



Di^ctission and Correspondence: — 



The Misuse of Technical Terms : Professor D. 

 W. Bering . Correction : Professor Jacques 

 Loeb 1028 



Notes on Electrical Engineering : — 



Submarine Telegraphy: W. S. F 1030 



Notes on Engineering : — 



' Chilled ' Cast-Iron Forts ; The ^Air-Splitting ' 

 Train: Professor E. H. Thurston 1031 



Current Notes on Physiography : — 



Topographic Terms ; Moraines of South Dakota ; 

 Bulletin of the American Bureau of Geography; 

 Professor W. M. Davis 1032 



T/te Study of Electrical Pressure 1033 



TheNeio York State College of Forestry 1034 



T/ie Forthcoming Meeting of the British Association.\035 



Scientific Notes and Neius 1036 



and Educational Netos 1039 



MSS. intended for publication and books, etc., intended 

 for review should be sent to the responsible editor, Profes. 

 sor J. McKeen Cattell, Garrison-on-Hudson, N. Y. 



RHYTHMS AND GEOLOGIC TIME.- 

 Custom dictates that in complying with 

 the rule of the Association I shall address 

 you on some subject of a scientific charac- 

 ter. But before doing so I may be per- 

 mitted to pay my personal tribute to the 

 honored and cherished leader of whose loss 

 we are so keenly sensible on this occasion. 

 His kindly personality, the charm which 

 his earnestness and sincerity gave to his 

 conversation, the range of his accomplish- 

 ment, are inviting themes ; but it is per- 

 haps more fitting that I touch this evening 

 on his character as a representative pres- 

 ident of this body. The Association holds 

 a peculiar position among our scientific or- 

 ganizations of national or continental ex- 

 tent. Instead of narrowing its meetings 

 by limitations of subject matter or member- 

 ship, it cultivates the entire field of research 

 and invites the interest and co-operation of 

 all. It is thus not only the integrating 

 body for professional investigators, but the 

 bond of union between these and the great 

 group of cultured men and women — the 

 group from whose ranks the professional 

 guild is recruited, through whom the scien- 

 tific spirit is chiefly propagated, and through 

 whose interest scientific research receives 

 its financial support. Its aims and form of 

 organization recognize, what pure science 



* Eead to the American Association for the Ad- 

 vancement of Science at Nevp York, June 26, 1900, as 

 the address of the retiring President. 



