April, 1008.] 



KNOWLEDGE. 



81 



more typical star of this class, and I tliiak that, on the whole, the two 

 liydrogen lines como out still more distinctly than in the mightj' 

 Sirius. Other easy star of this class are .-1 Wair, Castor, Q Arietis, 

 a Ophiuchi, the stars o ! the Flouijh (witli the exception of a, and ij, 

 which are of different types), and Regidns. Stars of lesser 

 niaKoitude, such as a. Corona, are of course more difficult. 



" In stars of the second or solar type, the little instruments will 

 be able to show that t)iere are many sub-divisions of the family. 

 The great Arcfiirus allows many lines, but it is not such an easy 

 spectrum as Alde/jaran, which gives one of the fullest spectra which 

 can be seen with the means at our di8])0sal. In Pollux the lines 

 are finer and more difficult for the beginner, while in Capella they 

 are more difficult still. 



" Intermediate between these classes comes an easy and'beautiful 

 spectrum — that of Proc//on. 



" Befelgeu.se is perhaps the easiest and best example of the third 

 type ; just now it is very beautiful, as the star is so bi'ight. 

 O- Herculis is more delicately beautiful, but of course is a little 

 more troublesome for the beginner, as it is of considerably less 

 magnitude. Antares is very fine, but owing to its southern 

 declination is difficult to get free of atmosphere. S Virpitiis is 

 pretty beyond words, but is not for beginners. ^ Pegasi is easy 

 and typical. 



" The possessor of the small instruments should by all means 

 look at Rigel and other bright stars of the Orion type, but he must 

 not be disappointed if he sees no lines ! neither will he see much 

 in Spica, which is also of this type ; nor, I am afraid, in o Cggni, 

 which is a standard spectrum in its way. 



" He should also look for the bright C line of hydrogen in 

 y Cassiopeire ; I have not yet seen it myself, but I mean to ! 



" A man with these small means must not expect to see every- 

 thing at the first glance. The hand needs to be trained as well as 

 the eye, as there is no driving clock to keep the stars in the field, 

 but after a little experience the observations are of the greatest 

 possible interest.*' 



PHOTOGRAPH OF THE NEBULA ROUND THE 

 STAR DM. NO. 980, ZONE 34^ IN THE 

 CONSTELLATION AURIGA. 



By Isaac Roberts, d.so., f.r.s. 



The photograph annexed delineates the region in the sky 

 between R.A. Sh. 7m. 56s. and E.A. 5h. 11m. 53s., and in 

 Declination between 33° 44''2 and 34° 48'0 north. The 

 area, therefore, is 3m. 57s. in extent from following to 

 pn-rfdiiig. and 1° 3'"8 fi'oni north to south. Scale — one 

 millimi-tre to 155 seconds of arc. 



Co-ordinates of the fiducial stars marked with dots for 

 the epoch 1900 :— 



St:i.r (.) DM. No. 978. Zone +?A° R.A. .5h. 9lii. ISs. Doc. 34° 18'-8. 



Mag. 7 8. 

 Stjir {..) DM. No. 98.5. Zone +:«" R.A. .Mi. lOia. ms. Deo. 34" S'-J. 



Mas;. 9-2. 



The description given of this nebula in Dr. Dreyer's 

 Index Cntalogu.e, No. 405, with the names of Schaeberle 

 and Max Wolf, is as follows : — Star G'7 mag., with pretty 

 bright, very large nebula. 



The [ihotograph was taken with the 20-inch reflector, 

 and exposure of the plate during ninety minutes on the 

 14th January, 1902, and the star referred to in the 

 paragraph above is DM. No. 980, zone 34°. It is involved 

 in the denser part of the nebulosity on the photo-print 

 annexed, at 30 millimetres aouth followinij the fiducial 

 star (.), but on the negative its image is very clearly 

 shown in the midst of the nebulosity. This condition of 

 obscuration is unavoidable on all copies made from the 

 original negatives, when there is both dense and very faint 

 nidmlosify on the same plate, becatise the faintest stars, 

 the condensations, and structural details in many of the 

 nebula:!, though they are visible on the negatives, cannot 

 be reproduced on copies made from them without sacrificing 

 the relative (iroportious of the density of the nebulosity as 

 a whole, and thus causing a less accurate perception of the 

 nebula. If we reduce the density of parts of the nebulosity. 



when making a copiy, for the purpose of showing more of 

 the involved details of the structure, the reader should be 

 informed of the fact so that he may not be misled into 

 making erroneous inferences when comparing photographs 

 with each other. 



On referring to the annexed photograph it will be seen 

 that the nebula is apparently placed in a crowded field of 

 bright and faint stars in the Milky Way, but we are not 

 warranted in assuming that the normal stars we see 

 scattered over its surface are involved in the nebulositv. 

 There are many star-like condensations in the nebtila that 

 doubtless are now undergoing the process of development 

 into stars of the normal type, which, after a lapse of 

 millions of years, may form a cluster of stars such as eye 

 observations and photographs have revealed to us as existing 

 in various parts of space. 



The nebula measures, ^mit 33^ minutes of arc from 

 north to south, and^jGKnutes iToistfoll&unng to preceding 

 on the nega^Oi^ J'b^e ai^ eJcipnsions of very faint 

 jJSioe, be jond the limit of the 

 5icpii,,w,i«, uiiey are too faint for copying. 

 iu(?Waea. The ij^^ma would extend to 75 

 minutes ot"ar^lii noith MM^ng to sonth preceding direction, 

 andaS^M^^tes in ^^Srjollowing to north preceding. This 

 fainr^nebutbsj.tj^*s of a flocculent character, with broad 

 tortuous viiw, m it which trend in diverse directions. 



The nebula is one of a class of which we now possess 

 many photographic delineations on a scale sufiiciently 

 large for measurements and for scientific investigations, 

 which work we are now and for some time past have been 

 engaged upon. 



MAN'S PLACE IN THE UNIVERSE.* 



By E. Walter Maunder, f.r.a.s. 



Perhaps the greatest drawback under which Science — not 

 one science alone but each and all of the sciences in turn — 

 labours at the present time is the impatience of the general 

 public to receive precise, definite, and striking results. 

 Thus, for example, most popular scientific lecturers find 

 that their audiences look to them to lead up to some clear, 

 crystallised conclusion. It demands some courage, and 

 great skill, to press home upon a popular audience the 

 truth that just in proportion to the advance of our 

 knowledge so is the increase in the number of the problems 

 which are presented to us for solution. The horizon 

 recedes as we advance, and, more than that, it widens at 

 the same time. 



A striking example of the eagerness with which the 

 conjecture of a scientific tnan wiU be caught up, if only it 

 be sitflicifully definite and far-reaching, is afforded by 

 Miidler's celebrated suggestion that the sun with its 

 attendant planets niight lie travelling in a gigantic orbit of 

 which the focus might be within the group of the Pleiades. 

 In how many thousands of essays, lectures, books, and 

 sermons the statement has apjieared that science has proved 

 that the centre of attraction of the universe is located in 

 Alcyone, the chief of the Pleiads, it would be useless to guess. 

 Contradicted a thousand times, the legend seems to have 

 lost- none of its pristine vigour. Give a fable a yard's 

 start, and Truth appears to be unable to overtake it in less 

 than a century. 



We greatlv fear that just such another myth has been 

 started on its career, imd by one of the most highly and 



• " Man's Place in the Universe, 03 indicated by the \ew Astro- 

 nomy," bv Alfred Ruasel Wallace, d C.l., f.r.s. Fortnighllg Seview, 



Minvl., I'lii:! 



