no CARNBGIS INSTITUTION 



and other items, whose cost is so uncertain that I prefer to estimate 

 the total expenditure at $200,000 for all such objects. 



There has been prepared a scheme of expense for maintenance, 

 including salaries of a director, at $5,000 ; an assistant director, at 

 $3,000 ; two assistants, at $2,000 each, with mechanicians and others 

 specifically named, which, with subsistence (necessarily to be pro- 

 vided by the observ'alor>') , materials, etc., aggregates $35,000 a year. 



It is estimated that $300,000 and interest will provide for this for 

 eleven years, and that the total expense of the distinctly solar ob- 

 servatory for the eleven-year period will be covered by the already 

 named sum of $500,000. 



.The provision of a great southern subtropical observatory, if 

 associated with this, will doubtless involve a far larger expenditure, 

 which is not here immediately considered. 



What here is immediatel)'' considered is the idea of a distinctly 

 solar obser^'-atory, and even this not solely for its scientific interest, 

 but for its imtaense possible utilities to the whole human race. 



I may say, in illustration, that I am f>er.sonally deeply interested 

 in the study of nebulae. I can not but see, however, the enormous 

 difference in quality between this study and that of the vSun, for all 

 the nebulae in th'.; sky might be blotted oi't without affecting the 

 price of a laborer's dinner or the material comfort of a single human 

 being. What shall we say of a similar contingency to the Sun ? 

 While a slight variation in the radiation of the Sun may corceivablj'^ 

 cause the death of millions of men by famine, it certainly seems 

 worth while to look at it from its utilitarian as well as from its 

 purely scientific interest. 



It is the possible immense utility of the solar observatory that I 

 dwell lipon, and concerning which I may borrow the weighty word.? 

 of Professor Newcomb m a similar connection, and state that astro- 

 nomical research in this direction may bring to light not merely in- 

 teresting cosmical processes but " cosmical processes pregnant with 

 the destiny of our race, ' ' 



S. P. LangIvEY. 



\_S. P. Langley io Mr. Walcott^ February 28, iqo2.'\ 



February 28, 1902. 

 Dear Mr. Walcott : 



\oa were saying to me that you knew of some persons who might 

 be desirous of aiding, through the Smithsonian Institution, some 



