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SCIENGK 



[N. S. Vol. IX. No. 222. 



maintain an astronomical observatorj' of the 

 first order. 



2. If so, what ends should such an institution 

 have in view, especially to what classes of astronom- 

 ical observation and research should it be devoted f 



Such classes of observation and research 

 should be conducted as will be of the utmost 

 practical utility : 



(A) Observations for determining the precise 

 positions of the stars upon the celestial sphere. 



(B) Spectroscopic observations of precision 

 for determining the motions of fixed stars toward 

 and from the solar system. 



One telescope of exceptional size should be 

 devoted to this work. 



(C) Determination of the distances of the 

 principal fixed stars. 



(Z>) Accurate evaluation of the elements con- 

 cerned in the motion of the earth's pole of rota- 

 tion. 



A zenith telescope of the best construction, 

 preferably photographic, should be constantly 

 employed upon this research. Cooperation 

 with the Coast and Geodetic Survey, and the 

 uninterrupted support of an additional observer 

 in Manila or Honolulu, is highly desirable. 

 This service should be maintained with the 

 utmost rigor for at least twenty-five years. 



(E) Meridian observations of position of the 

 sun, moon and major planets. 



Planetary observations should be converted 

 into errors of celestial longitude and ecliptic 

 north polar distance, and equations formed con- 

 necting these errors with the elements of the 

 planetary tables used in the preparation of the 

 Nautical Almanac. 



(F) Searching investigation of the constant 

 of meridian refraction should be conducted 

 uninterruptedly throughout a series of years. 



(G) Equatorial observations not previously 

 specified. These need be but few. 



(-H) Solar research in several departments. 



1. The spots, their number and area, photo- 

 graphically and visually. An independent 

 record should be maintained in either Manila 

 or Honolulu, thereby supplementing, at half 

 intervals, the similar work at Greenwich, Dehra 

 Dim and the Mauritius. 



2. The prominences, photographically and 

 visually. 



3. The faculffi, with the spectroheliograph. 



4. The corona, during total eclipses, chiefly 

 photographically. 



5. The Sun's Reversing Layer. 



6. Bolometric investigation of the infra-red 

 rays of the solar spectrum. 



7. The permanency in character or the sec- 

 ular variation of lines in the solar spectrum. 



8. The permanency or secular variation of 

 the solar constant. In the prosecution of 6, 

 7 and 8 a high-level station might advan- 

 tageously be maintained, in either Hawaii or 

 southern California. 



(/) The department of the Astronomical 

 Ephemeris and Nautical Almanac should not 

 only prepare and publish this work, at least 

 three years in advance, but should issue also 

 accessory publications of especial service to 

 navigators. 



(J) Magnetic observations ought to be main- 

 tained, as regards declination, dip and in- 

 tensity. 



(K) A time-service must be maintained, not 

 only for the purpose of the Navy, but for the 

 wide distribution of standard time and the 

 dropping of time-balls at important localities. 



The Superintendent or Director of the gov- 

 ernment observatory should be held respon- 

 sible for the efficient prosecution of all branches 

 of the work under his charge and for its prompt 

 publication. Also he should be empowered to 

 choose his subordinates, with or without ex- 

 amination, their recommendation for appoint- 

 ment to be subject to approval by a Board of 

 Visitors at semi-annual sessions. Advance- 

 ment and discharge should be regulated in a 

 similar manner. 



David P. Todd. 



Obseevatoky House, Amherst, Mass. 



To the Editor of Science : To the three 

 questions submitted to me a few days since by 

 yourself I would reply as follows : 



1. It is most emphatically desirable that the 

 government of the United States should support 

 a National Astronomical Observatory. There 

 are certain important lines of astronomical re- 

 search which are of a character such as not to 

 appeal to the popular interest and which, if 

 left to be taken care of by private endowment, 



