April 12, 1900] 



NATURE 



575 



greatest success in every direction, notable among the results 

 being Barnard's photographic delineation of comets, nebulne, 

 and the Milky Way, and the magnificent spectroscopic work 

 of the Henry Draper Memorial carried on by Prof. Pickering 

 at Harvard College. 



Within the last few years the energetic director of the 

 Harvard College Observatory has been enabled to extend his 

 operations by the erection of a well-equipped observatory in 

 the clear air ofArequipa, Peru, spectroscopic and other data 

 on a uniform plan for the whole celestial vault being thus 

 secured. Prof. Pickering has, in fact, developed the photo- 

 graphic side of his work into a wonderful detective force, so 

 perfectly organised that no new star of reasonable brightness 

 can escape detection, and no important change in a known 

 star go unrecorded. The munificent gifts to the Harvard Ob- 

 servatory have thus, in Prof. Pickering's hands, been put to the 

 best possible uses. 



The work of the Lick Observatory is also largely photo- 

 graphic. Here, the great refractor has been employed with the 

 greatest success by Prof. Campbell in photographing the spectra 

 of nebulne and bright line stars. More recently special attention 

 has been given to the photographic determination of stellar 

 velocities in the line of sight, with the result that a dozen or so 

 of spectroscopic binaries have already been detected, Polaris 

 and Capella being among the most interesting systems thus 

 recognised. Quite recently, marvellous results have been ob- 

 tained by Prof. Keeler in photographing the forms of nebulte 

 with the Crossley reflector. The Director's report for the year 

 ending September i, 1899, indicates a remarkable state of 

 activity among the comparatively small staff of this observatory. 

 The success of these observers is doubtless in some measure 

 due to the wisdom displayed in the limitations which they have 

 set to their work. A well-defined programme, and concentration 

 upon it, appears to be the policy adopted, and the truly scientific 

 spirit which controls their investigations is exhibited by the 

 following remarks from Prof. Keeler's last report : "Comets 

 which are bright enough to be easily seen at the leading 

 observatories receive only occasional attention, while comets 

 which, by reason of their faintness or unfavourable position, 

 are difficult of observation, are followed as closely as possible. 

 . . . The Lick Observatory makes the most of its natural 

 advantages ; and extended theoretical researches, which can be 

 made as well in a city as at a fine observing station, do not form 

 part of our general plan." In this way the output of useful 

 observations is greatly increased, and the co-ordination of 

 different facts can be carried on by workers generally. The 

 same spirit prevails at Harvard Observatory, where "prece- 

 dence has been given to physical work, since less attention is 

 paid to such work elsewhere," and the photographic records 

 there accumulated have been placed at the service of any one 

 properly qualified to discuss them. 



The Yerkes telescope, i.i the hands of Burnham, Barnard 

 iind Hale, has already been very productive. One of the most 

 important pieces of work undertaken here is the photographic 

 registration of the spectra of the Piscian (111.(5) stars ; and the 

 wealth of detail recorded in such difficult objects is truly re- 

 markable. 



But it is by no means only in observatories furnished with 

 giant telescopes that astronomical science has been advanced. 

 Admirable work has also been done in unpretentious establish- 

 ments, and, indeed, with no observatories at all. Gould's in- 

 vestigation of the Milky Way and the distribution of stars is a 

 case in point, and to lake another example, a vast amount of 

 energy has been expended in perfecting the American Ephenieris 

 and Nautical Almanac. Chandler's masterly investigations of 

 the variations of terrestrial latitude also demand separate 

 mention. 



Terrestrial researches bearing on astronomical phenomena 

 have not been neglected. Newcomb and Michelson's deter- 

 minations of the velocity of light are classical examples, and 

 among more recent work reference may be made to Rowland's 

 determinations of the origins of a vast number of Fraunhofer 

 lines, and to Humphrey's and Mohler's investigations of the 

 displacement of spectrum lines due to pressure. 



It will be seen, even from this incomplete statement, that the 

 output of astronomical work in America has been very great, 

 and there is every indication that it will go on increasing. The 

 rapid development is doubtless due to various causes, not least 

 among them being the unstinted support given by private 

 benefactors. The American astronomers undoubtedly also owe 



UO. 1589, VOL. 61] 



a great debt to their opticians an\J engineers, the Lick and 

 Verkes refractors, with their apertures of 36 and 40 inches 

 respectively, being the crowning triumphs of the instrument 

 makers. Messrs. Alvan Clark's telescopic object glasses have 

 long been justly held in high estimation all over the world, and 

 the skill of Messrs. Warner and Swasey has been fully equal to 

 the task of successfully mounting their mammoth productions. 



Some of the success of the Americans may perhaps be at- 

 tributed to their wise selection of sites for their instruments, 

 when they have been free to exercise their judgment. The 

 Lick Observatory, at an elevation of 4000 feet, is favoured with 

 exceptionally good atmospheric conditions, and the sites of the 

 Verkes and various other observatories were only decided upon 

 after very careful trials. 



Instrumental equipment and good climate, however, are not 

 the only requisites for a successful observatory. Much depends 

 upon the men at the little ends of the telescope tubes, and, we 

 may add, upon the men at their desks or in their laboratories, 

 who bring their minds to bear upon the explanation or utilisa- 

 tion of the phenomena observed, besides suggesting further 

 observations. The training of astronomers is therefore of as 

 much importance as the provision of instruments. Fortunately, 

 America can boast of unparalleled facilities for this necessary 

 training. Students' observatories abound, and in many cases 

 instruction of the most advanced character is obtainable. Of 

 elementary instruction it is scarcely necessary to speak ; but 

 American students are to be congratulated if the teaching gener- 

 ally is on such enlightened lines as those indicated in Miss 

 Byrd's " Laboratory Manual of Astronomy," and Prof. Todd's 

 "New Astronomy." A most valuable paper, by Prof. E. S. 

 Holden, on the teaching of astronomy in primary and secondary 

 schools and in the university has recently been published.^ 

 During the early years of a child's school-life, the lessons must 

 necessarily be simple ; and Prof. Holden gi vesan extremely sugges- 

 tive sketch of the methods which should be folio wed, bearing in mind 

 that " the main point is to open the eyes and mind, and the sun 

 and stars are convenient for the purpose." To the teachers of 

 astronomy in secondary schools Prof. Holden also gives many 

 valuable hints. Here astronomy is to be regarded as an "in- 

 formation study," as well as an educative one, and suggestions 

 as to simple apparatus to facilitate the teaching are given. 



From our present point of view, however, the most interest- 

 ing part of Prof. Holden's paper is that referring to the courses 

 of instruction in astronomy offered by some of the American 

 universities and colleges. Particulars are here given of the in- 

 struction carried on in fifteen institutions, and they illustrate in 

 the most satisfactory manner the advantages enjoyed by the 

 American student who wishes to acquire an extended know- 

 ledge of the subject. The courses are in several cases remark- 

 ably comprehensive, and in five of them astrophysics takes an 

 important place in the curriculum. In every case there appears 

 to be an adequate supply of instruments and observatories, and 

 for students desiring to specialise there are abundant oppor- 

 tunities of entering even the best observatories. 



The course at the University of Chicago is perhaps the most 

 complete, but the syllabus is too long for quotation ; suffice it 

 to say that it includes every department of theoretical and 

 practical astronomy, the astrophysical instruction being carried 

 on at the Yerkes Observatory by the distinguished staff of 

 resident professors and observers. The Director of the Yerkes 

 Observatory some time ago made the following statement as to 

 the relation of that establishment to the work of students : — 



"After completing the necessary preliminary work in Chicago, 

 students who desire to devote special attention to observational 

 astronomy or to astrophysics are admitted to the Yerkes Ob- 

 servatory at Lake Geneva, where they are given every possible 

 facility. In addition to pursuing the courses of instruction 

 enumerated in the Annual Register of the University of 

 Chicago, students at the observatory may take part in the 

 regular work of research. As soon as they have had sufficient 

 preliminary training, they are encouraged to undertake original 

 investigations of their own." From other notices we gather 

 that this privilege is not restricted to students from Chicago. 



At the University of California also an admirable course of 

 astronomy is offered, one item of which may be quoted as 

 illustrating the attention given to practical work : — 



" 4 A. Practical astronomy. Lectures and observatory work. 

 Navigation and nautical astronomy. Practical work in the 



1 " Report of the Commissioner of Education, 1897-98." Vol. i. p. 869. 

 (Washington, 1899.) 



