376 



SCIENCE. 



IN.S. Vol. XV 111. No. 45o 



vestig-ation, as distinguislied from administra- 

 tion and teaching. I desire at this time to 

 indicate specifically, by way of illustration, 

 the thought which at that time I endeavored 

 to express. My illustrations are taken alto- 

 gether from the Departments of Mathematics 

 and the Natural Sciences. On a future oc- 

 casion I shall use material which has been 

 gathered from the departments ordinarily 

 classed as the humanities. 



The proposition which I wish to present is 

 this: Nearly every member of every depart- 

 ment in the university is to-day engaged in 

 investigative work in which effort is being put 

 forth to make new contributions toward the 

 better understanding of the subject studied. 

 I think it best under all the circumstances not 

 to mention in this statement the specific names 

 of persons thus engaged. In most cases, how- 

 ever, the mention of the subject itself will 

 carry with it a knowledge of the person en- 

 gaged in the work. 



THE DEPARTirEST OF ASTRONOMY AND 

 ASTROPHYSICS. 



Mr. A is engaged in a sj'stematic study of 

 double stars with the forty-inch telescope. 

 His great general catalogue of all known 

 double stars in the northern heavens, which 

 he has been preparing during the past twenty- 

 five years, is about to be published by the 

 Carnegie Institution. 



Mr. B is engaged in a spectroscopic study 

 of stellar motions with the forty-inch telescope. 

 The results he has already published represent 

 the highest degree of precision hitherto at- 

 tained in this field. Through his initiative 

 several observatories in Europe, Africa and 

 the United States are cooperating in the ob- 

 servation of certain standard stars. The re- 

 sults of his investigations will serve as a 

 basis for general studies of stellar relationships 

 and motions, and also of the motion of the 

 solar system with respect to the stars. 



Mr. C is at work upon a triangulation of 

 nearly 700 stars in various star clusters. 

 These observations will serve as a basis for 

 future investigations of the internal motions 

 of these clusters. His observations of the 



Fifth Satellite of Jupiter are the only ones 

 that have been obtained during the last five 

 years, on account of the diflieulty of observing 

 this exceedingly faint object. In the. co- 

 operative plan of observing the minor planet 

 Eros, participated in by many observatories in 

 all parts of the world, he has obtained the 

 most extensive series of observations, com- 

 prising over 1,500 measures on 73 nights. In 

 addition to many other mierometrical observa- 

 tions with the large telescope, he has under- 

 taken an extensive photographic survey of the 

 Milky Way and other objects with the Bruce 

 photographic telescope. 



Mr. D is engaged in investigations on the 

 motions of the minor planets, with particular 

 reference to the characteristic planets of the 

 Hilda type. He is also continuing his re- 

 searches on effective potential forces. 



Mr. E is engaged in a variety of theoretical 

 investigations, most of which involve the ap- 

 plication of the methods of modern mathe- 

 matics to problems of celestial mechanics. He 

 is giving special attention to a critical study 

 of the nebular hypothesis on dynamical 

 grounds, and is also at work on the theory of 

 telescope objectives, with special reference to 

 the use of non-spherical surfaces. 



Mr. E's work on the design and construction 

 of reilecting telescopes, and his photographs 

 obtained with the two-foot reflector of the 

 Yerkes Observatory have exercised a wide in- 

 fluence among astronomers. His color-screen 

 method of converting a visual telescope into 

 a photographic one has j'ielded excellent re- 

 sults with the forty-inch telescope and is being- 

 adopted in other observatories. 



Mr. G is engaged in spectroscopic studies 

 of various stars with the large telescope. This 

 work relates particularly to certain very close 

 double stars discovered by Mr. B and Mr. G 

 with the Bruce spectrograph. 



Mr. H is engaged in determining the bright- 

 ness of a large number of stars, particularly 

 those which vary in their brightness and which 

 at minimum are beyond the reach of ordinary 

 telescopes. Part of this work on very faint 

 stars has been done in cooperation with two 

 or three of the largest observatories in this 

 country. 



