SCIENCE 



FRroAY, April 7, 1916 



CONTENTS 

 The Distances of the H avenly Bodies: Dk. 



W. S. ElCHELBERGEE 475 



Methods of Teaching Electrical Engineering : 

 Professor Dugald C. Jackson 483 



The Joseph A. Holmes Safety Association . . . 487 



Convocation WeeJc Meeting and the American 

 Chemical Society 487 



Virst Meeting of the Pacific Division of the 

 American Association for the Advancement 

 of Science 489 



i?c Notes and News 490 



and Educational News 494 



Discussion and Correspondence: — 



Seminary Courses in the History of Science: 

 Professor Wm. H. Hobbs. Democratic Or- 

 ganisation in a College Department: Pro- 

 fessor P. L. Washburn 495 



Scientific BooTcs: — 

 Pirsson and Schuchert's Text-iooTc of Geol- 

 ogy: Pkoeessoss Hervey W. Shimer and 

 Frederic H. Lahee. Pearl on Modes of 

 Sesearch in Genetics: Professor H. E. 

 Walter. Fumes 's Introduction to the 

 Study of Variable Stars: Dr. J. A. Park- 

 hurst 497 



The Vital Equilibrium: Dr. E. A. Spaeth. 502 



Special Articles : — 



Natural Cross Pollination in the Tomato: 

 Donald F. Jones 509 



Societies and Academies: — 



. The American Philosophical Society 510 



' MSS. intended for publication and boots^ etc., intended for 

 reriew should be sent to Professor J. McKeen Cattell, Ganison- 

 Qn-Hudson, N. Y. 



THE DISTANCES OF THE HEAVENLY 

 BODIESi 



A YEAR ago our retiring president took 

 the members of the society into his confi- 

 dence as follows : 



Cognizant of the fact that my election to the 

 presidency of the Philosophical Society a year ago 

 obligated me to give an address of some sort one 

 year later, I confidently waited for the inspiration 

 that I felt would suggest a fitting sub."jeet for the 

 occasion. The expected inspiration did not, how- 

 ever, materialize. 



Undoubtedly because of that fact, and 

 out of the goodness of his heart, towards 

 the close of his address he turned to the 

 present speaker, then presiding, and said: 



I have said nothing whatever about the determi- 

 nation of the distances between the planets nor 

 of the units used by astronomers in reckoning dis- 

 tances of the stars. . . . They form, so to speai, 

 other chapters of the subject which I shall leave 

 to some future ex-president of our society. 



This call, I suppose, was intended to take 

 the place of an inspiration, and, wherever 

 I have gone during the past twelve months 

 the call has ever been ringing in my ears. 

 The subject of the evening is presented 

 therefore not as a matter of choice, but from 

 compulsion. 



Before any attempt was made by the an- 

 cients to determine the distance from the 

 earth of any celestial body, we find them 

 arranging these bodies in order of distance 

 very much as we know them to-day, assum- 

 ing that the more rapid the motion of a 

 body among the stars the less its distance 

 from the earth; the stars, that were sup- 

 posed to have no relative motions, were as- 

 sumed to be the most distant objects. 



1 Address of the president of the Philosophical 

 Society of Washington, March 4^ 1916. 



