Sei'iesibki! 18, l!tO;i.J 



SCIENCE. 



ST 



Mr. .T's investi{?atioa« relate to tlie {lenerul 

 subject of stellar evolution, and are threefold 

 in character: 



1. Photographic studies of stellar spectra 

 for the purpose of determining the physical 

 and chemical condition and the order of de- 

 velopment of certain great classes of stars. 

 With the collaboration of two other members 

 of the department, he has just completed an 

 investigation of one of the two classes of red 

 stai"s, including their chemical composition, 

 physical condition, motion in the direction of 

 the earth, order of evolution and relationship 

 to the sun and other classes of stars. 



■2. Studies of the sun made for the purpose 

 of elucidating both solar and stellar phe- 

 nomena. 



3. Laboratory investigations bearing on 

 problems of solar and stellar chemistry and 

 physics. With the collaboration of another 

 member of the department, an investigation 

 of spark spectra in liquids and compressed 

 gases, and their bearing on the theory of tem- 

 porary stars, has just been completed. 



TllK DEPAItT^lEN'T (IF PIIVSK'S. 



Mr. A is engaged in work upon a ruling 

 engine for the production of diffraction gra- 

 tings of a high order of perfection. Serious 

 difficulties have been encountered, but consid- 

 erable progress has been made upon this most 

 important piece of work, and at present the 

 ))rospect of attaining the end sought is highl.v 

 encouraging. The efficiency of the gratings 

 which it is hoped this machine will make will 

 be at least twice that of the best gratings 

 which have yet been produced. The difficulty 

 of making a grating with twice the efficiency 

 is as much greater than that of making the 

 gratings which have been produced as the 

 difficulty of making a telescope objective of 

 eighty inches diameter is greater than that 

 of making one of forty inches diameter. 



Mr. A has also just begun an investigation 

 of the effect of various agencies upon the posi- 

 tion, breadth, distribution of light and in- 

 tensity of spectral lines. He further expects 

 to take up soon the problem of the velocit.v of 

 light. 



Messrs. li and C are engaged in the publica- 

 tion of a series of text-books which contain 

 the most important of the undergraduate 

 courses in physics which have been developed 

 here. This work is considered necessary in 

 order that the university may exert an ade- 

 quate influence upon physics-teaching through- 

 out the country. Two of these texts have 

 already appeared and two more are nearing 

 completion. 



ilr. B is also cooperating with the Depart- 

 ments of Mathematics and Pedagogy in an 

 endeavor to improve the teaching of mathe- 

 matics and physics in the secondary schools, 

 and is about to begin the collection of Mr. 

 A's scattered works for publication in a sin- 

 gle volume. 



Mr. C is, in addition, engaged in an inves- 

 tigation of the nature of electric discharge 

 in high vacua. This investigation is de- 

 signed to test an important point in the mod- 

 ern electron theory of matter. 



Mr. D is in the midst of a research upon 

 the relation of the sparking potential and the 

 spark distance for distances of the order of 

 the mean free path of the molecule. 



Mr. E is assisting Mr. A in the perfection 

 of the ruling engine, and is also cooperating 

 with Mr. C in the production of a physics 

 text-book for elementary schools. 



Ifr. F is engaged upon two pieces of re- 

 search: (1) an examination of the conditions 

 which govern the coherence between metals; 

 and (2) the influence of hysteresis upon elec- 

 tric resonance. Preliminary results of these 

 investigations were presented by Mr. F to 

 the American Association for the Advance- 

 ment of Science at its recent meeting in 

 Washington. 



Mr. G is determining the index of refrac- 

 tion of sodium vapor for that portion of the 

 spectrum which contains the sodium lines. 



TlIK DKI'ARTMKNT OF til KMISTRV. 



^ir. A is at jiresent engaged upon a study 

 of dissociation phenomena in the glycerine- 

 gl.vcol series, as well as in the .sugar group. 



Mr. B is making a study of equilibrium 

 conditions in calomel vapor, and also between 

 amorphous and soluble sulphur. 



