6 CARNEGIE INSTITUTION OF WASHINGTON. 



with the additional proviso that in so doing he is certain to 

 entertain an inadequate estimate of the aggregate of these investi- 

 gations. The items here cited, therefore, should be regarded as 

 indicating the diversity of the Institution's work rather than as 

 emphasizing any part of it. 



Astronomy is at once the oldest and the most popular of the 

 sciences. The immensity of the masses, the immensity of the 

 distances asunder, and the majestic phenomena of the heavenly 

 bodies appeal strongly to the imaginations of all classes of men; 

 while the pecuUar objectivity of astronomical studies has been 

 of inestimable value in developing the reflective capacity of 

 mankind. It seems safe to assert, indeed, that up to the present 

 time astronomy has done more than all other sciences combined 

 to assist man in learning how to orient himself aright in the 

 universe of which he forms a relatively insignificant part but in 

 which he plays the unique role of interpreter for his contempo- 

 raries and for his successors. It is no accidental circumstance, 

 therefore, that the Institution should have given so much atten- 

 tion to the promotion of astronomical science, or that the Solar 

 Observatory should have attracted so much popular interest. 

 This interest has been enhanced during the past year by the 

 essential completion of the 100-inch reflecting telescope. All of 

 the serious difficulties of this great enterprise have been success- 

 fully overcome; and the parts of the instrument will doubtless be 

 assembled for use during the coming year. The Solar Observa- 

 tory will thus possess an unrivaled equipment for nearly all 

 branches of stellar work except that of positional astronomy, to 

 which the Institution is contributing substantial aid through its 

 Department of Meridian Astrometry. It should be understood, 

 however, that material equipment does not constitute an effective 

 observatory. Much more important elements are to be found in 

 the men who are able to design, to construct, and to use such 

 equipment. 



Of all the innumerable masses of the universe of interest to us 

 the earth easily ranks first. It is the only one of these masses 

 immediately accessible to us. It has served as a foundation for 

 studies not only of the solar system but of the similar stellar 

 systems, and it has given rise to many sciences, ranging from 



