Aug. 1, 1884.] 



♦ KNOWLEDGE ♦ 



93 



the planet, and the way in which this contrasts with the 

 inner portion, or "terminator" (Knowledge, vol. iii., 

 p. 222), shading off into the bright sky. The two little 

 cusps, too, 80 sharp and bright, will certainly catch the 

 eye, from the want of correspondence of their inner edges 

 with the interior curve of the planet's lighted surface. 

 All this seems indicative of a dense and extensive atmo- 

 sphere surrounding Venus. One effect of the inner shading 

 is worthy of note, and that is the effect it has in 

 reducing the area of the planet which should be theo- 

 retically illuminated. It we draw a plan of the orbit 

 of Venus we shall see that at her greatest elongation 

 she ought geometrically to be dichotomised, i.e., exactly 

 half-full ; but it will be seen that in reality she is rather 

 less than this, the degradation of light towards the 

 terminator being pretty rapid. Observers of repute have 

 seen the terminator jagged and uneven, like that of the 

 moon ; but it is too much to expect of a .3inch telescope 

 that it should exhibit such difficult features as this. A 

 blunting of one or both of the horns has also been perceived 

 at times by various astronomers, both in this country and 

 on the Continent. And, what is of considerable interest 

 to the possessors of instruments of the size employed for 

 the purpose of these papers, very faint dusky spots and 

 bright patches have been perceived from time to time in 

 telescopes of the most varying apertures ; small ones show- 

 ing these spots as well as, in fact better than, some of the 

 larger instruments. This may possibly arise from the 

 creneral glare of light in a large objective or mirror deaden- 

 ing the eye to such delicate details. It is by the aid of 

 these spots, real or imaginary, that the hypothetical period 

 of rotation of Venus has been determined. 



But, however beautiful and curious the spectacle may be 

 which is presented by Venus in quadrature, it will scarcely 

 interest the student so much as his first view of her in 

 inferior conjunction. Our succeeding figure exhibits the 



Yic. 2. — Venus in Inferior Conjunction, July 11th, 1884. 

 Power 160. 



planet as seen in the same instrument and with the same 

 power as that employed to make our first sketch with. The 

 contrast between these two aspects of Venus will arrest the 

 attention at once. The comparatively small half-moon has 

 become converted into a hair-like glittering semicircle 

 of light, enclosing something which is certainly darker 

 than the surrounding sky. The very abnormally 

 hazy condition of the atmosphere which has now 

 persisted for many months was against the percep- 

 tion of any very delicate gradations of shade, so that 

 the whole of the dark body of Venus was invisible ; 

 but the effect, difficult or impossible to reproduce in a 

 wood-cut, was that of a disc dark where embraced by the 



crescent of light, and fading into the light of the sky out- 

 side or beyond the cusps. On the occasion of former 

 inferior cocj unctions, the whole of the planet's dark limb 

 has been unmistakably perceived. In order that it may be 

 seen to the greatest advantage, a veri/ small diaphragm 

 should take the place of the ordinary one between the two 

 lenses of the Huyghenian eye-piece. A blackened card 

 disc with a fine hole made centrally in it with a red-hot 

 needle, answers capitally. The hot needle bums the fringed 

 edge of the perforation and leaves it clean and sharp. The 

 smaller the bole, consistently with distinct vision, and the 

 more sky light that is cut ofl', the sharper and better will 

 the body of the planet appear. This little device will 

 always be found useful when any body is to be viewed in 

 bright sunlight. 



There is a queer story — or, perhaps, it would be more 

 correct to say a series of queer stories — with reference to 

 various observations of a satellite or companion to Venus, 

 situated always close to the planet, sometimes on one side 

 of her, sometimes on the other, but always exhibiting a 

 phase identical with her's. The most feasible explanation 

 of this is that it has had its origin in each case in what is 

 called, "a gho.st" in the eye-piece, i.e., in a reflection of the 

 )ilanet's image from the convex surface of the eye-lens on to 

 the plane surface of the field-lens, and so back to the eye of 

 the observer. An observation made by Short, the famous 

 optician, in 1740, who did use two different telescopes, 

 seems the only one to throw any legitimate doubt upon this 

 explanation. SI. Houzeau, the eminent Belgian astronomer, 

 however, is so convinced of the objective reality of the 

 various apparitions of this satellite that in Ciel et Terre 

 for May l-ith of the present year he gravely propounds 

 the hypothesis that a little planet (which he provisionally 

 names Neith) revolves round the sun in an orbit just ex- 

 terior to that of Venus herself. Here there is an oppor- 

 tunity for the student to distinguish himself. He has only 

 to watch Venus day and night until he picks up this 

 attendant, to do so. Whether, though, he succeeds, or 

 whether he fails in this attempt, he will find himself amply 

 repaid for any amount of labour by the diversified but always 

 beautiful appearance of the planet as she speeds on her 

 path round the sun, and may find infinitely less profitable 

 ways of spending his time than by the devotion of a daily 

 half-hour to watching Venus in a Three-Inch Telescope. 



BKITISH SEASIDE RESOETS, 



FROM AN UNCONYENTIOXAL POINT OF VIEW". 

 By Percy Russell. 



II- 



TAKING all England, and making proportional allow- 

 ance for inland as against sea-coast populations, it 

 would probably be found that the line of shore between 

 Cromer on the north-east and the Bill of Portland on the 

 south-west, is the best-known, perhaps, of all the coast of 

 England to the greatest number of people. If, per contra, 

 we take the much more sinuous shore-line from Portland 

 Bill by Start Point, Falmouth, the Lizard Head, the Land's 

 End, and then northwards to the splendid estuary of the 

 Severn, and thence to St David's Head, that western head- 

 land of Pembrokeshire, we shall follow a coast-line that, 

 except at a few points, is unknown in detail as it is un- 

 visited by the multitude, but which includes some of the 

 finest scenery of these islands, being in many cases a happy 

 blending of the rugged grandeur of north-west Britain with 

 the softness and almost the climate of Italy itself. The 



