3i8 



NATURE 



[Fed. 1 8, 1875 



are catalogued in identical positions, but he finds they are dis- 

 tinct stars, and the companion to 2 410 is of 19 mag. of Herschel's 

 scale. The com]5anion of 2 2749 shows an increase in distance 

 and angle ; the three stars are now almost in a line. The posi- 

 tion of 2 38S appears to have increased 100' since 1835. — J. 

 Pebbutt gives position observations of Coggia's Comet, together 

 with comparison stars. J. C. Watson sends a note on his dis- 

 covery of Planet (139) at Pekin. — The elements and an ephe- 

 meris of Borrelli's Comet of December 1874 are given by J. 

 Holetschek. 



Comet 1874, VI. 



T= Oct. 18.7391 Berlin time. , 



v = 298° 46' 38" 



a = 281° 38' 18" 



i = 99° 25' 43" 

 log-?= 9. 71576. 



— Burnham notes the discovery of a close companion to 

 j3 Leporis, dist. 2", pos. 269°'!, loth mag. This appears to 

 have been missed by Herschel. — Prof. Bredichin gives differential 

 measures of position of Juno and adjacent stars. — A number of 

 position observations of the minor planets are given by Kowalczyk. 

 — A lithograph of various appearances of Coggia's Comet, drawn 

 by Vogel, accompanies this number. 



SOCIETIES AND ACADEMIES 



London 



Royal Society, Feb. 11. — " Some particulars of the Transit 

 of Venus across the Sun, December 9, 1S74, observed on the 

 Himalaya Mountairjs, Mussoorie, at Marz-Villa .St.ition, lat. 

 30° 28' N. , long. 78° 3'E. Height above sea, 6,500 feet." — Note 

 No. I. By J. H. N. Hennessey, F.R. A.S. ..Communicated by 

 Prof. Stokes, D.C.L., Sec. R.S. 



The author observed the event with the equatoreal of the 

 Royal Society, which Capt. J. Herschel, R.E. , in his absence 

 from India, had temporarily placed at his disposal. His especial 

 object in view was to ob.^erve the transit from a cciiuiderahU' 

 height, and this condition was easily secured through the cir- 

 cumstance that he was located only fourteen miles from Mus- 

 soorie, on the Himalaya Mountains. His numerical results 

 will be communicated very shortly in a second note. The 

 remarks here made are restricted chiefly to what he smo with 

 the equatoreal. 



The telescope of the equatoreal has a 5-inch object-glass, with 

 about sixty inches focal length, and is driven by an excellent 

 clock. 



The author found from actual trial that the most suitable eye- 

 piece lor both ingress (sun's altitude 2° 24' to "f' 29') and egress 

 (sun's altitude about 26°) was one of 125 power. He selected for 

 ingress two glasses which, combined, gave a neutral or bluish 

 field ; and for egress he changed one of these for a deep-red glass, 

 so that the field now presented a moderately deep red. The 

 glasses were quite flat, and lay against one another in intimate 

 contact, giving excellent definition. He enjoyed most exquisitely 

 clear weather during his observations. 



In describing the phenomena of the transit, the author has 

 occasion to speak of Venus as she appeared across the sun's 

 limb, when one portion of her own limb is seen against the sun, 

 and the other remains against the sky. The former portion he 

 calls Venus's sun-limb, or V^, the latter Venus's sky-limb, or 

 V,;. Again, he requires to mention a ring of light around Vj^, 

 which he indicates by L,;, the corresponding ring around V„ 

 being understood by L„. Another point is this : anyone who has 

 watched, say the sun's limb, especially at a low altitude and with 

 high power, must be aware of the turmoil or ebullition which 

 there appears, very like as if the limb was being boiled. He 

 denotes this kind of turmoil by "boiling." 



The author did not detect Venus's limb until after it had made 

 an indentation on the sun's limb. The latter boiled sensibly, 

 but by no means violently. It appeared jagged, and as if with 

 minute spikes projecting inwards, all of which were well defined 

 in the bluish field. Watching V„, he found it also boiling slightly, 

 but in a manner somewhat different to the sun's limb. The 

 appearance was that of boiling vapour coming round from the 

 face of Venus, turned towards the sun and overlapping V„ ; 

 moreover, this boiling was not restricted to the edge of V,„ but 

 extended 2" or 3" beyond, thus forming a kind of boiling annulus, 

 in which there were minute sparkling specks dancing and 



shifting about, appealing and disappearing ; the edge V„ was 

 seen through the boiling. 



Neilher pear-drop nor ligament was seen either at ingress or 

 egress. 



Col. Walker, who was at Dehra Doon, in the valley below, 

 some ten miles south of Mr. Hennessey's position, writing to the 

 author, states that he "saw the pear-drop and the ligament very 

 distinctly." 



After describing his own observations, the author concludes as 

 follows : — 



1. In view of the light-ring Lj., and of the peculiar boiling 

 annulus around V„, which may be called L„, I have no doubt 

 that L„ was, in fact, a continuation of the light-ring L|j, which 

 latter, beyond all question, was plainly lisible ; and under these 

 circumstances it may be urged that Venus is surrounded by an 

 atmosphere which at the time was made visible to the extent of 

 2" to under 4" in breadth. 



2. As a matter of fact, the pear-drop or other ligament was 

 visible at a height of 2,200 feet, but at 6,500 feet the ligament 

 was invisible. The influence generally of height of station, from 

 this evidence, appears undeniable ; but the phenomenon still 

 remains to be accounted for definitely. If, however, an effective 

 atmosphere of .i- breadth around Venus be conceded, this atmo- 

 sphere may be supposed to stop a certain amount of direct light 

 from the sun, producing a slight shade around Venus corre- 

 sponding to the breadth -r. This shade would, I conceive, be 

 quite invisible when its outer edge is backed by the sun's bright 

 light ; but could we contract the sun to a diameter equal to 

 that of Venus ///(.t twice .r, and make Venus and the sun con- 

 centric, it appears likely that we should see a shaded annulus 

 right round Venus between her limb and that of the sun. 

 Further, that the annulus would appear darker at low than at 

 higher altitudes, and would become invisible when the observer 

 was raised above a sufficiency of the earth's atmosphere. Should 

 these suggestions prove tenable, the ligament seen would break 

 when the outer edge of the shade, corresponding to -v, transited 

 across the sun's limb. 



3. Solar light shining through Venus's atmosphere, if any, 

 produces no alteration in the lines of the solar spectrum, so far 

 as the dispersion of a single simple prism can show. Also, 

 Venus's face, turned towards us, reflects no light during transit, 

 subject to the same instrumental test. 



"Appendix to Note, dated November 1873, on White Lines 

 in the Solar Spectrum," by J. H. N. Hennessey, F.R.A.S. 

 Communicated fjy Prof. Stokes, Sec. R.S. 



After detection of the white lines 1650 .and 1658 (Kirchhoff's 

 scale) at Mussoorie in November 1873, I discovered two other 

 such lines before leaving that station of observation, viz. 2009 

 and 206S (about). On 2Sth November, 1S73, I packed up the 

 spectroscope, taking particular care that the prisms should not 

 shift from the position they then occupied. 



On 28th November, 1873, I set up the spectroscope in the 

 Dome Observatory at Dehra, in the valley below, the prisms 

 retaining their former position, and my recollection of the white 

 lines seen at Mussoorie being still quite vivid. I now found that 

 1650 and 1658 were distinctly seen ; but they were no longer 

 nearly of the pure white colour they presented at the higher 

 station, while what may be termed the gloss about their white- 

 ness, which induced me to describe them as resembling "threads 

 of white silk held in the light," had quite disappeared ; indeei" 

 they were now so decidedly greenish as not to invite attention 

 White line 206S I now could hardly see, and 2009 was invisible,' 

 notwithstanding that I was quite familiar with the positions they 

 occupied, and had made careful notes on the subject. 



After this I released the prisms and turned them about 

 variously, without producing any alteration in the white lines as 

 they were now seen. 



"The height of the spectroscope above sea-level was — 



At Mussoorie 7100 feet. 



„ Dehra ... 2200 „ 



Anthropological Institute, Feb. 9.— Col. A. Lane Fox, 

 F.S.A., president, in the chair. — The President exhibited a 

 series of stone implements from the Alderley mines of Cheshire, 

 and Dr. J. Simms exhibited five Lapp skulls. — A paper by the 

 Rev. Wentworth Webster was read on the Basque and the Kelt, 

 an examination of a paper by Mr. Boyd Dawkins, F.R.S., on 

 the northern range of the Basques, in the Fortnightly Rei'ieiu of 



ds 



