Djecember 6, 1901.] 



SCIENCE. 



879 



neglected elsewhere, either because they 

 are too expensive or for other reasons. It 

 is believed that the policy of undertaking 

 neglected work, and doing what is most 

 needed and not what is most attractive, 

 would commend itself to Congress, to as- 

 tronomers and to the people. 



The Naval Observatory should cooperate 

 with the other observatories of the country, 

 use its influence to prevent needless dupli- 

 cation of work, and supply important de- 

 ficiencies in work done elsewhere. 



Great care should be taken in preparing 

 a permanent scheme of work in the prepa- 

 ration of which the opinions of experts in 

 each department should be carefully con- 

 sidered. 



Important changes in such a plan should 

 be made only after careful consideration, 

 and should in general relate to details of 

 observation, reduction and form of publi- 

 cation, rather than to objects or classes of 

 investigation. The officers required to 

 carry out this work should be selected for 

 special fitness or experience, as well as for 

 general astronomical knowledge, and a 

 change in duty should be seldom made and 

 then only for important reasons. If any 

 observer has by years of experience attained 

 great skill with a meridian circle, to place 

 him in charge of an equatorial would be 

 much like making a sailing master of an 

 engineer, however skilled he may be. 

 Great care should be taken in the assign- 

 ment of duties to difftirent members of the 

 observing staff in order to secure a satisfac- 

 tory distribution of force among the instru- 

 ments and to avoid undue concentration or 

 the reverse. At the same time the special 

 aptitudes of individuals should be kept in 

 mind, and their interest enlisted by giving 

 them as far as possible independence of 

 responsibility. 



The following provisional plan is sug- 

 gested for criticism and amendment : 



The meridian circle is necessarily one of 



the most important instruments in a gov- 

 ernment observatory. Daily observations 

 should be made, whenever possible, of the 

 sun and moon, and of sufficient number of 

 standard stars to determine accurately the 

 error of the standard clock and the con- 

 stants of the instrument. The major 

 planets should be observed on a certain 

 number of nights every year to correct 

 their ephemerides, but not often enough to 

 curtail seriously the other work of the in- 

 strument. A system of standard stars 

 should be selected by cooperation with the 

 various national almanacs and observa- 

 tories, and a certain number of observations 

 of each of these stars should, if possible, be 

 secured each year. In planning the obser- 

 vations, the determination of their absolute 

 and not merely their relative positions 

 should be taken into consideration. In 

 preparing a list of standard stars it is sug- 

 gested that instead of attempting to observe 

 all stars brighter than a given magnitude, 

 it might be better to take only those of 

 about the same magnitude and spectrum) 

 in order to eliminate errors due to magni- 

 tude and color, and to choose those nearly 

 equally spaced in the sky, adding such 

 polar and equatorial stars as will culminate 

 at nearly equal intervals and will not inter- 

 fere with one another. It would also be 

 necessary to include all the very bright 

 stars as a basis for daylight observations. 

 As examples of special researches that 

 might have been taken up under such a 

 system may be mentioned the comparison 

 stars for Victoria and Sappho proposed by 

 Dr. Gill in 1889, and the comparison stars 

 selected by the Astrophotographic Confer- 

 ence of 1900 for observations of Eros. 



The altazimuth instrument should per- 

 haps also be used for observing the moon 

 when off the meridian, and for determining 

 the time when clouds render it impossible 

 to observe on the meridian. The observa- 

 tion of zenith stars should be continued 



