December 19, 1901J 



NATURE 



155 



cyclone to the south ; and no doubt that theory is 

 attractive and has much evidence in its favour. But 

 the gales which burst from the E.S.E. or S.E. were 

 invariably accompanied by a sudden and great rise of 

 temperature, which in eleven cases cited ranged from 

 nearly 14 to more than 44 Fahrenheit degrees. This wind 

 beat against Cape Adare from the level surface of the 

 frozen sea, and does not suggest a Fohn effect or an 

 origin in the icy heart of a South-Polar anticyclone. 

 Does it not rather indicate the passage of a cyclone 

 centre to the north and the sweeping in of air from the 

 warm surface of the sea south of Australia? An anti- 

 cyclone brooding over the southern land would probably 

 tend to turn wandering cyclones eastward along its 

 margin, and the two explanations are thus to some 

 extent compatible. 



The magnetic observations are being worked up by 

 Dr. Chree ; from the preliminary figures quoted here we 

 note that the greatest dip observed was 88^ 2' 37" at the 

 base of the Mount Melbourne, but it is pointed out that 

 the magnetic dip all along the coast of Victoria land was 

 less than at the time of Ross's expedition. The zoo- 

 logical chapter contains no information ; it merely quotes 

 a few descriptive remarks of the vertebrates noticed, all 

 of them of known species. The invertebrates are not 

 referred to, but the whole of the zoology of the e.xpedition 

 is being worked up at the Ijritish Museum. 



There was no geologist on board the Southern Cross, 

 but the non-technical descriptions of rocks in the 

 narrative and the reference to the determination of 

 specimens by Mr. J. T. Prior show that the geologist on 

 the Discovery will have a splendid field in which to win 

 his spurs, though the alternation of volcanic and 

 metamorphic rocks does not suggest the probability of 

 sensational fossil finds. 



The difficulty of making astronomical observations in 

 high southern latitudes is feelingly dealt with. The 

 determination of longitude was particularly difficult, the 

 only really satisfactory attempt to fix Cape Adare being 

 by an occultation of Saturn by the moon. Refraction was 

 a never-ceasing trouble, for the horizon was frequently 

 very far from being a straight line. Thus on one oc- 

 casion Mr. Bernacchi says (p. 156) : — 



" Huge icebergs to the north which must have been 

 quite thirty miles away, and which, under ordinary 

 circumstances, were invisible even from the huts, were 

 elevated by refraction to a height on a level with the top of 

 Cape Adare, the height of which is nearly 900 feet. The 

 display, it can almost be called so, was ever changing in 

 appearance ; sometimes one part of the horizon was 

 elevated, then this would subside 'and another part rise 

 up. At this time of the year the coast line in the direc- 

 tion of Vule Bay and Cape North, nearly 100 miles 

 away, was frequently seen on clear days in consequence 

 of the great rarity of the atmosphere." 



Acomparison of Mr. Borchgrevink'sand Mr. Bernacchi's 

 narratives yields several minor points of interest to which 

 it is unnecessary to refer ; but we find the resultant of 

 reading both books is an increase of our opinion of 

 the commander's power of overcoming difficulties and of 

 the physicist's scientific zeal and loyal cooperation. 



THE SPECTRA OF BRIGHT SOUTHERN 

 STARS y 



'T^HE well-known lesearches on stellar spectra which 

 -*■ have been carried on for many years at the Harvard 

 College Observatory under the direction of Prof E. C. 

 Pickering have now- reached another very definite stage. 

 The publication of the Draper Catalogue in 1890 put us 



1 "Spectra of Bright Southern St.irs, Photographed with the 13-inch 

 Boyden Telescope .-is a Part of the Henry Draper Memorial, and Discussed 

 by Annie J. Cannon under the Direction of Edward C.Pickering." (AuimU 

 of the Astronomical Observatory of Harvard College, vol. xxviii. pan ii.) 



NO. 1677, VOL. 65] 



in possession of the general characteristics of the spectra 

 of more than 10,000 stars, and this work will long remain a 

 monument to the skill of Prof Pickering, besides fulfilling 

 its original purpose as a lasting memorial of Dr. Henry 

 Draper (Nature, vol. xlv. p. 427). Following this, a 

 detailed description and classification of the spectra of 

 681 of the brighter stars north of —30^, based upon 

 photographs taken with relatively large dispersion, was 

 published in 1897 (N.VTURE, vol. Ivi. p. 206). The 

 establishment of a branch observatory in the southern 

 hemisphere, at Arequipa, Peru, has enabled Prof. 

 Pickering to extend the inquiry to the southern stars, 

 with results described in the volume under notice. 



The prismatic camera has been employed throughout 

 the whole investigation, and the accumulation of so much 

 valuable material in so short a time must be attributed 

 in great measure to the many advantages which this 

 instrument possesses over the slit spectroscope when radial 

 velocities are not in question. At Arequipa the 13-inch 

 Boyden telescope has been employed in conjunction with 

 one, two or three prisms, giving spectra of lengths 2'24, 

 4'86 and 7'43 centimetres respectively from Hf to H^s. 

 The number of photographs taken from November 29, 

 1891, to December 6, 1899, was no less than 5961, with 

 an average exposure of one hour ; but as many of the 

 spectra were photographed several titnes the number of 

 individual stars investigated is smaller, namely 1 122. 

 In these are included all stars south of declination -30° 

 which have a photometric magnitude of 5'o or brighter, 

 numerous fainter stars in the same region, many stars 

 between the equator and - 30', and a few northern 

 stars. 



Dr. McClean's magnificent series of photographs of 

 the spectra of southern stars had prepared us to find that 

 the spectra are not less diverse than in the northern 

 hemisphere, and it became a point of much interest to 

 see if the greater number of stars now studied neces- 

 sitated any revision of the classification proposed for the 

 northern stars alone. This question of classification, it 

 will be understood, is one of the greatest importance, 

 since the ultimate aim is not merely to enable the 

 astronomer to place his photographs in their proper 

 pigeon-holes, but to indicate the various stages of star 

 life. It is an unfortunate circumstance, however, that 

 not one of the classifications hitherto suggested has met 

 with general acceptance, but the reason for this may 

 perhaps be traced to a want of confidence due to the 

 frequent revisions which have been necessary as the 

 more delicate features of the spectra have been brought 

 to light by the use of better instruments. However that 

 may be, it is sufficiently remarkable that the old classifi- 

 cation which we owe to Rutherfurd and Secchi is almost 

 the only approach to a universal language of stellar 

 spectra, in spite of the fact that it is hopelessly in- 

 adequate to deal with modern data. 



For the present discussion Miss Cannon has found it 

 convenient to revert to the nomenclature of the Draper 

 Catalogue, but with modifications to suit the intermediate 

 classes revealed by the use of greater dispersion. It is 

 pointed out that in most cases the symbols can be 

 readily translated into the numbers previously applied 

 to the groups of northern stars, but it would surely have 

 been more convenient to have two such closely associated 

 investigations expressed in the same language. How- 

 ever, the classification is fairly adequate, but as the 

 nomenclature is too cumbersome to be likely to come 

 into common use it is unnecessary to describe it in 

 detail. 



The great majority of the 1122 stars discussed in this 

 publication can be arranged in a sequence, agreeing in 

 the main with that arrived at in the case of the northern 

 stars, but permitting its extension towards the beginning 

 of the series. The investigation of the northern stars 

 led Prof Pickering and Miss Maury to commence the 



