REPORT 0]? THE PRESIDENT, IQII. 23 



was made by the Executive Committee at its meeting of November 17, 1910, 

 and the wrecked buildings have been replaced during the past summer by 

 structures at once more secure and more commodious. 



On account of lack of quarters the Director has been able to afford facili- 

 ties for research at the laboratory to only eight investigators. Nevertheless, 

 the year has proved fruitful in important advances. One of these, attained 

 by Mr. G. H. Drew, of Cambridge University, relates to the role of certain 

 bacteria in depriving surface sea water of nitrogen and in precipitating the 

 vast deposits of chalky mud (oolite) of the Florida-Bahama region; another, 

 by Dr. T. W. Vaughan, records definite progress in his quantitative deter- 

 minations of the growth of corals and coral reefs ; while the Director and his 

 collaborators have published twenty-one papers, mostly included in volumes 

 Nos. 132 and 133 of the publications of the Institution, 



As already explained in a preceding section of this report, the meridian 

 determinations of stellar positions at the temporary observatory at San Luis, 

 Pj - Argentina, were finished in January, 191 1. This comple- 



Meridian tion in an unexpectedly short time of the more formidable 



Astrometry. p^^.^ q£ ^j^^ Undertaking of the department in the southern 

 hemisphere leaves only the minor task in photometry of measuring the mag- 

 nitudes (or brightness) of those stars for which this property has not been 

 hitherto measured. This task, requiring only two observers and light equip- 

 ment, will be subject to small expense. 



In the meantime the deductions of stellar positions and motions are pro- 

 ceeding expeditiously in the computing section of the department at the Dud- 

 ley Observatory; so that the final catalogue, giving precise positions of all 

 stars up to the seventh magnitude inclusive, may be expected to appear in due 

 time. As often happens in such extensive scientific investigations, many by- 

 products are arising of hardly less importance than the primary ends in view. 

 One of these, deduced from the Director's preliminary Star Catalogue, pub- 

 lished by the Institution about two years ago, shows the mean velocities rela- 

 tive to the solar system of stars of different spectral types. The values de- 

 rived from the "proper motions" of the catalogue are in striking agreement 

 with those derived for the same stars by Prof. W. W. Campbell from direct 

 measurements of the motions of these stars in the line of sight. The remark- 

 able result which is thus brought out from independent investigations is that 

 the speed of a star through space increases with its age. Attention is here 

 invited to the Director's interesting summary of this by-product in his cur- 

 rent report, the investigation in full having been published in the Astronomi- 

 cal Journal, April 3, 1911. It is of interest to note in this connection that the 

 independent investigations of Campbell, referred to above, were also carried 

 out by aid of grants made by the Institution. 



