212 REPORTS ON INVESTIGATIONS AND PROJECTS. 



ASTRONOMY. 



Schlesinger, Frank, Allegheny, Pennsylvania. Grant No. 422. Completion 

 of parallax computations begun under direction of George B. Hale. 

 (For previous reports see Year Books Nos. 6, 7.) $300 



The computations made under this grant were completed in 1908, in which 

 year the principal results were briefly communicated to the Astronomical and 

 Astrophysical Society of America at its annual meeting at Put-in-Bay, Ohio. 

 Shortly afterwards the derived parallaxes were made generally available to 

 astronomers through the compilation of stellar parallaxes made by Kapteyn 

 and Weermsa (Groningen Publications of the Astronomical Laboratory, 

 No. 24). 



Owing to the pressure of more immediate duties, time to prepare this work 

 for detailed publication was not forthcoming until last winter. With the 

 approval of the President of the Carnegie Institution of Washington, the 

 Astrophysical Journal was selected as the medium of publication. Seven 

 papers appeared in consecutive numbers of this Journal (vol. xxxii. No. 5 ; 

 vol. XXXIII, Nos. 1-5, and vol. xxxiv. No. i), of which 400 reprints (in 

 book form) have been secured, and have been distributed among the lead- 

 ing observatories and astronomers. These reprints bear the title "Photo- 

 graphic Determinations of Stellar Parallax made with the Yerkes Refractor, 

 under the auspices of the Carnegie Institution of Washington, D. C." 



The chief distinctive features of this work are ( i ) the sacrifice of a reduc- 

 tion in accidental errors in order to exclude systematic error as far as possi- 

 ble; (2) the elimination of guiding error by means of a rotating disk of 

 adjustable aperture, and (3) the use of a very short and entirely rigorous 

 method of reduction. 



In spite of the sacrifice in the matter of accidental error, it appears that 

 with a telescope of this size and character, the number of stellar parallaxes 

 that can be determined per annum with a probable error of d=o.'''oi3 will (in 

 the long run) be about equal to the number of clear nights available for this 

 work. 



BIBLIOGRAPHY. 



Fletcher, Robert, Army Medical Museum, Washington, District of Columbia. 

 Grant No. 711. Preparation and publication of the Index Medicus. 

 (For previous reports see Year Books Nos. 2-9.) $12,500 



The volume of the Index Medicus for 191 1 has been issued in its usual 

 monthly numbers to the present time. Some important additional subdi- 

 visions have been introduced. Two especially interesting titles may be men- 

 tioned, namely. Anaphylaxis and "606." The latter, more generally known 

 as Ehrlich's remedy for syphilis, or as Salvarsan, has provoked a large 

 amount of discussion. The general subject of syphilis in accordance with 

 present views has been placed under "Parasitic diseases." 



