KNOVSALEDGE ♦ 



[Sept. 18, ] 



possible. If the Andromeila neLula were an outlyins- galaxy 

 of the same i^ize as oui' own, it must lie at a distance 

 exceeding at least a hundred times that of the remotest 

 star in our galaxy. Now the stars in the outermost part do 

 not give one-thousandth part of the light of an eighth 

 magnitude star. Removed a hundred times farther away 

 those outlying stars would be reduced 10,000 times in 

 lustre, and so would not give the 10,000,000th part of 

 the light which comes to us from the star now shining 

 in the Andromeda nebula. It would have to be 30,000 

 millions of times larger than our sun, if its surface- 

 lustre resembled his — and it has been shown by St. Claire 

 Deville and others that we cannot safely assume a much 

 greater surface-lustre than our sun's to be even possible. 

 If we admitted the sudden development of sach an 

 appallingly stupendous mass as this, the bare possibility 

 of so wonderful a sun forming in the heart of a star-cloud 

 would prevent otir admitting the belief that that star- 

 cloud could be a galaxy like our own. Thus the outburst 

 of the new sun definitely negatives the belief that any 

 external galaxies are within range of our keenest tele- 

 scopic vision. The grand thought that there is a system 

 higher than the stellar system, a system of galaxies, must 

 remain, probably for ever, a conception — like the Kantian 

 idea of yet higher orders of systems. 



But as to the system of solar systems, the discovery 

 just made gives positive evidence of the most interesting 

 kind. Wliile compelling us to draw the nebula; back, as it 

 were, from the remotely external position which had been 

 assigned to them, it enhances our conceptions of the variety 

 and vitality within the mighty system we can explore. 

 Enabling us now definitely to regard all orders of nebulse 

 as part of our stellar system, it teaches us to see in that 

 galaxy a complexity of structure far surpassing, as we 

 might have anticipated, even the amazing complexity 

 we had already recognised in the solar system. We not 

 only see within the stellar system all the varied orders of 

 suns, and all the wonderful varieties of arrangement 

 among suns — double, triple, and multiple groups, cluster- 

 ing aggregations, streams, branches, nodule.s, and far- 

 reaching clouds of suns — but we see all the varied orders 

 of star cloudlets — globular, elliptical, ring-shaped, and 

 spiral, resolvable and irresolvable, star dust, and star 

 vapour — within the bounds of the same marvellously 

 variegated system. "We recognise also not only all the 

 stages of sun-life already noted, not only the evidence of 

 solar decay and death, but evidence of changes which 

 imply the first stirrings of solar life. In vitality, as in 

 variety, the great galaxy is to our conceptions infinite, 

 even as it is infinite in extent and in duration. 



The following letters have also appeared : — 

 "Respecting the new star in Andromeda it is announced 

 irom Brussels that at the commencement of Atigust the 

 stellar nucleus was not visible. Mr. Isaac W. Ward, how- 

 ever, reports having seen it on August 19, at 11 p.m. It 

 was also seen at Rheims, by M. Lajoye, on August 30, and 

 nlso independently by Mr. G. T. Davis, of Theale, near 

 Reading, on September 1. The Dtm Echt telescopes 

 .show it as a veritable 7\ magnitude star, with a fairly 

 continuous spectrum. On September 3, Lord Crawford 

 and the undersigned found that the Nova is most probably 

 situated some TGs. jn-eceding and 5" south of the old 

 nucleus, which is much overpowered by the light of the 

 star. " Ralph Copelasd." 



"With reference to the remarkable change that has 

 taken place in the great nebula 31 Messier in Andromeda, 

 I was fortunate enough to obtain an observation of it last 

 night with my 10| inch Calver reflector. The new star 



was estimated at about 7'5 magnitude, orange-red in 

 colour, and very hazy, not showing a clean disc with any 

 power; it was followed by a most minute point of light 

 at about twenty to thirty seconds of arc, the space 

 between being darker and apparently devoid of nebulous 

 matter. Whether this latter was a star or merely a 

 ' knot ' in the nebula I could not determine owing to 

 want of light. 



" A change of such magnitude in a nebula which has 

 hitherto resisted all attempts to resolve it into stars is an 

 event of such importance that it is to be hoped no oppor- 

 tunities will be lost to detect any further change that 

 may take place, and no doubt the spectroscope will prove 

 most valuable. 



" As Mr. Knobel points out, it may be only the out- 

 break of one of those extraordinary variable stars of 

 which T Coronas (the "Blaze" star of 18G6) is a good 

 example ; but I venture to think some great change has 

 been taking place in the nebula itself, for as far back as 

 the beginning of July I found the central portion much 

 more condensed than usual, and so bright as almost to 

 convey the idea of a stellar nttcleus, although no absolute 

 star point was visible. The evidence of actual change at 

 this time, however, was not conclusive enough to warrant 

 a public announcement. Kesxeih J. Takraxt." 



"I have received a memorandum on the above subject 

 from the Rev. S. H. Saxby, of East Clevedon, Somerset, 

 from which, by his permission, I extract some interesting 

 particulars. 



" On August 6, Mr. Saxby, who was then at Davos, 

 observed the nebula, and remarked its singular bright- 

 ness. On August 9, which was a very clear night, he 

 examined it again, and describes it as follows : — ' The 

 whole central portion of the nebula was strikingly bright. 

 .... There was no sign whatever of a stellar nucleus, 

 nor was there anything which could so much as raise the 

 question of the existence of one. The centre of conden- 

 sation was purely nebulous, and the condensation was not 

 abnormally rapid.' Mr. Saxby also examined the spec- 

 trum of the nebula, hoping that he might be able, on so 

 clear a night, to detect some bright lines in it, but 'got 

 nothing more than the usual dull, continuous spectrum, 

 deficient at the red end,' although the nebula in Tulpe- 

 cula showed its bright lines readily. The following 

 night, August 10, gave precisely the same results. 



" On returning to England Mr. Saxby examined the 

 nebula again on Sept. 3, at 9.30 p.m., and was astonished 

 to see a bright star in its centre, and at once commu- 

 nicated his discovery to me. The next morning he 

 learned of Dr. Hart wig's prior observation of the 

 change. 



" I may add that I examined the spectrum of the new 

 star at the Royal Observatory on Friday, Sept. 4, with 

 the large ' half- prism ' spectroscojje devised by the Astro- 

 nomer-Royal, and found it to be of precisely the same 

 character as that of the nebula — i.e., it was perfectly con- 

 tinuous, no lines, either bright or dark, being visible, and 

 the red end was wanting. There is, therefore, at present 

 no evidence of an}- outburst of heated gas, as was the 

 case with the 'temporary' stars T Coronis in 1866, and 

 'Nova' Cygniin 1876. 



" The star itself was very easily seen in the finder of 

 3 in. aperture attached to the large refractor of the Royal 

 Observatory. "Edwakd W. Mausdee." 



" The new star in Andromeda was observed here on 

 Saturday and Sunday nights, Sept. 5 and 6. It is very 

 nearly of the seventh magnitude, and of a yellow colour, 

 similar to Ai'cturus, with continuous spectrum. It is 



