544 



NA TURE 



[October 7, 1897 



in their true positions of passing near the several radiant-centres, 

 but directed upwards and downwards alternately, for each 

 radiant-point in turn, so as not very sensibly to confuse each 

 other. The lines are also drawn of such lengths as to show 

 by ending at different border-lines of the diagram, at what 

 date, or approximate date (for the few Perseids' paths noted on 

 July 20, 23, 25-6, 28, and 31, and on August 4 and 6 are re- 

 ferred to the nearest special dates, by their line-lengths, only) 

 in July or August any path-line was observed. In this way 

 the progress of the radiation is either visible in its main out- 

 line at a glance, or any special peculiarities and features of it 

 may be studied closely in detail. 



It may thus be noted easily that although not dying out for 

 some days longer, the activity of shower I. was chiefly confined 

 to the first week (up to July 27) of the watch ; while the 

 meteors of shower II., first appearing only on July 30, con- 

 tinued, with a maximum on August 2, to show themselves 

 brightly up to August 3 ; and that little was to be seen of the 

 main stream of rj-Perseids (shower IV.) until August 2-3, when 

 it was still inconspicuous, but when a precursor limb of it, the 

 intermediate shower III., was about as active beside shower II. 

 as it again became afterwards on August 8, but more feebly on 

 August 9, beside the plentiful displays then going on, of the 

 showers IV. and V. from tj Persei and B, C Camelopardi. 



The offshoot as it seemed of the main shower's radiation, 

 at the latter place, showed like the main stream itself, but 

 slight signs of its existence, either in July or later, until August 6, 

 when four of six meteors (all Perseids), seen in an hour, diverged 

 very distinctly from a point thus first well indicated near B, C 

 Camelopardi. On the nights of August 8 and 9 it appeared to 

 form an almost equally intense companion-shower to the tj- 

 Perseids ; and as it seems to conform well in its position to the 

 straight onward line of motion of the other Perseid centre- 

 points, and to add apparently another link-step to the regular 

 earlier stages of a chain-like progression, it might have been 

 expected, had the nights of the loth and nth of August not 

 been such unfavourable ones for noting any further changes in 

 these loci of divergence, that with the expiration of the 17- 

 Perse'id shower IV., the accompanying stream V. from B, C 

 Camelopardi, would perhaps survive it, or else would on some 

 later night reappear with a new and naturally much weaker 

 maximum agreeing with its theoretically "proper apparition-date. 



Some future years' clear skies, it may be hoped will allow 

 the after-showers of Perseids, already very clearly and distinctly 

 traced by Mr. Denning, to be seen and noted in not less 

 splendid weather than that which so well and continuously dis- 

 played the phases of the preceding showers' appearances in the 

 present year. 



Several exceptionally bright meteors, and some smaller ones 

 presenting specially remarkable features of appearance, were 

 noted in my watch, which, together with the real paths ob- 

 tained from corresponding observations at other places of some 

 of the shooting-stars and fireballs of its list, would furnish me 

 with a sufficient abundance of interesting notes to fill another 

 letter. But the subject of the latter meteors will be discussed 

 more satisfactorily and completely in a general review of the 

 collected observations which Mr. Denning and Mr. Corder are 

 conducting ; and satisfactory descriptions of the former meteors 

 would involve more searches among known radiant-points, with 

 full deductions of their radiant-centres for the 167 sporadic 

 meteors of my list, than I have yet attempted, to summarise 

 correctly the points of leading and rather novel interest which 

 were presented by the radiations of some of the more particu- 

 larly striking meteors. I must forego, therefore, a review of 

 features of interest, and of real path conclusions which some of 

 the individual meteors offered very attractively for description, 

 although I felt at first much prompted to describe them ; in 

 order to place their discussion in the hands of those much better 

 and more surely able than myself to judge of their importance, 

 who in combination with Mr. Denning undertook the arduous 

 task of collecting and the necessarily much slower and more 

 dilatory task of abstracting and collating all these numerous 

 descriptions. A. S. Herschel. 



Observatory House, Slough, September 21. 



been unable to distinguish segmentation. The worm is entirely 

 luminous. The phosphorescence has precisely the bright 

 greenish colour of the light emitted by the glow-worm. The 

 light is under control. When in glow its secretion is luminous, 

 as is seen in its trail and in the phosphorescence imparted to 

 the hands when handled. It is said by the owner of the grass- 

 plat that the casts are luminous. This is a point I have had no 

 opportunity of observing. 



At night the slightest irritation suffices for lighting-up. 1 

 captured one in a small clod of turf, to transplant in my grass- 

 plat. The very slightest pressure of the clod, which I should 

 have thought inappreciable, brought on a manifestation of light. 

 On nights when not on the crawl and not otherwise visible, a 

 favourite expedient is to stamp on the ground to get them to 

 come to the surface. The worms in response at once rise to 

 the surface and light up, as though it were possible for them to 

 show fight, instead of, like other worms, scampering away. 



The spot colonised is far from humid, but the worms are more 

 active in wet than in dry weather. The worm is new to this place, 

 and, as far as my researches go, it has not been observed westward 

 in Wales. It seems to me to be an instance of Liimbriciis phos- 

 phoretcs, but it hardly agrees with the published description of 

 that organism. I want to avoid depleting the colony, or putting 

 any of the inmates to torture, but I could at least furnish a 

 specimen. J. Lloyd-Bozward. 



Worcester, September 27 



Appearance of a Noddy in Cheshire. 



The other day,' when looking through a collection of stuffed 

 birds, I saw and obtained a specimen of the Neddy Tern {Sterna 

 slolida, Linn.). It is in immature plumage, the white on the 

 crown being only just visible. 



It was shot on the Dee marshes in winter about six years 

 ago. 



As I believe this Tern has been only twice recorded as visiting 

 Europe, I think this specimen worth mention. 



Neston, Cheshire, September 29, F. Congreve. 



A Colony of Highly Phosphorescent Earth-Worms. 



In the sheltered westward corner of a small grass-plat in this 

 city there is a colony of highly phosphorescent earth-worms. 

 The annelid is round, pellucid, slender, of a faint yellowish tint, 

 is about two inches long, and is not flattened behind. I have 



NO. 1458, VOL. 56] 



THE ETNA OBSERVATORY. 



A RECENT number of La Nature (No. 1262) con- 

 tains an interesting illustrated account of the 

 observatory on Mount Etna, a building which was 

 originally designed by Prof. Tacchini for some special 

 investigations which he had in hand. The eruption 

 which occurred in 1886 caused much disaster, and con- 

 siderably affected the building which was not restored 

 till the year 1891. In the observatory at the present time 

 there is an equatorial of 5 "5 metres focal length, besides 

 various meteorological and seismographical instruments. 

 Observations are made regularly, except in the winter 

 months. This year a very important addition will be 

 made by the setting up of telegraph and telephone wires 

 as far as Nicolosi, thus rendering it possible to regulate 

 the work. 



The ascent from Catania, which town lies at a distance 

 of about 30 kilometres in a southerly direction, is made 

 by coach as far as Nicolosi (700 metres). One proceeds 

 then by mule as far as Casa del Bosco (1440 m.), and to 

 the Alpine meteoi-ological station (1890 m.) ; this latter 

 place being half-way between Nicolosi and the observ- 

 atory. The rest of the way is made by foot over the 

 snow ; the path, which is very rough, can be ascended by 

 mule in the summer, but it is impossible in the winter, 

 owing to the great accumulation of snow. The observ- 

 atory is sometimes buried in the snow to a depth of two 

 to five metres, admission being then only possible 

 through the first-floor windows. 



The disadvantages of Mount Etna as an observing 

 station are therefore due more to the snow than to 

 volcanic disturbances. Long periods elapse between 

 the volcanic outbreaks, during which time the surface 

 near the central crater and the observatory is quiet, so 

 that even the most sensitive seismograph may be used. 



