Jan. 5, 1883.] 



KNOWLEDGE 



11 



and with all respect to the memory of worthy Mr. Thomas 

 Day, " Sandford and Jlerton " is occasionally rather weari- 

 some, and the science in it is not always either plainly 

 worded or exactly described. The fight between Harry 

 Sandford and Master Nash seemed to us the best thing in 

 the book — not because it was a fight (we trust), but 

 because the bad fellow got well beaten. But Mr. Barlow, 

 with his preposterous stories, was an emphatic nuisance 

 most of the time, and so was Harry himself, too often. 

 Tommy Merton was a good deal pleasanter, except for the 

 short time when fine company and a silly mother spoiled 

 him. Our modern writers of stories for boys seldom intro- 

 duce a bore of the Barlow sort. They get their boys out 

 into the open, and give them multitudes of exciting scenes 

 — in fact, their worst fault (and it is not one of which boys 

 arc likely to complain), is that they represent travel in the 

 woods, at sea, in arctic regions, and in the tropics, as a 

 scene of constant adventure. There are no flashes of 

 dulness, as in real travel. 



The book before us is a capital book for boys. A lad 

 with a taste for natural history, li\-ing with a kindly but 

 rather weak uncle, and an aunt who sets a stern face 

 against litter of all sorts, gets into trouble at home, culmi- 

 nating when he stuff's a grey parrot into the semblance of 

 a " beast," — a " regular guy." Then an uncle of kindred 

 tastes appears on the scene, and the boy, after some pre- 

 liminary lessons in shooting, boating, and so forth, goes 

 with him to New Guinea, there to have his fill of collect- 

 ing, adventure, and danger, — yet not absurdly lucky, as 

 some boys we could name, in always meeting just such 

 adventures as a traveller, after ten or twelve 

 years in a place, would consider the most remark- 

 able in his experience. Nor is our " Nat, the 

 Naturalist " too murderously inclined. He peppers 

 bloodthirsty Papuans with small shot, reserving his rifle- 

 bullet for closer danger when danger seems almost at its 

 closest. As in Mr. Manville Fenn's " Ship Ahoy !" dangers 

 thicken at times till there seems no hope ; but a way of 

 escape is always found (we are not taking away the interest 

 of the story in saying so much, for no boy hero that we 

 know of was ever killed, at least in such stories as this — 

 the boy on the burning deck don't count). The tone of the 

 book is thoroughly good. The science is not rammed down 

 the boy-reader's throat, but brought in naturally and 

 pleasantly. The hero is not an impossible combination of 

 courage, strength, agility, and keenness, but a boy who 

 masters his fears after failures, and becomes active, strong, 

 and clever by resolute work and watchfulness. 



THE FACE OF THE SKY, 

 FROM JAXUAEY 5 TO JANUARY 19, 1883. 



UXDFR this hp.iding we propose to point out, at intervals of 

 fourteen days, such celestial objects and phenomena as arc 

 susceptible of observation by the amateur possessor of a portable 

 achromatic telescope. Pending the completion of the stellar 

 portion of '" Nighis with a Three-Inch Telescope," our references to 

 objects of interest in the various constellations will* be confined to 

 those which have been previously described in these pages. It is 

 further proposed to furnish a popular description of the lunar 

 surface in a series of papers especially devoted to that subji-ct. 

 Hence, references to the moon will, for the present, be confined to 

 notices of her age and position in the sky. 



The snn should be examined every clear day with a power of 60 

 or 70, and an eye-shade of the tint known by the opticians as 

 ■'London smoke" (or by one of the darkest blue or green pro- 

 curable), as we are now passing through a period of sun-spot 

 maxima, and the solar stu-face is diversified by spots and faculic, 

 some of the former occasionally assuming enormous dimensions. 



To-night (Jan. 5), if it be (as is most unlikely) absolutely clear 

 in the south-west horizon, Mercury may be caught twinkling close 



to it, immediately after sunset. The chief constellations visible 

 after dark are Pisces, Cctus (Knowledoe, Vol. I., p. 220), Pegasus, 

 Cygnus (Vol. 11., p. 310), Copheus, Perseus (Vol. 1., p. 221), 

 -Vndromeda (id.), Cassiopeia (Vol. 1., p. 445), Draco (Vol. II., 

 p. 330), Ursa Major (Vol. 1., p. 445), Ursa Minor (id.), 

 Auriga (Vol. I., 313), Taurus (Vol. 1., p. 221), Gemini (Vol. 

 I., p. 376), Orion (Vol. I., p. 290 and 291), &c. The 

 references we have given aro to the places in which the chief 

 objects of interest in the shape of double star and nebula? ia these 

 constellations aro described. For a general view of the night sky, 

 however, the student may refer to the map on p. 20G of our first 

 volume ; from which, moreover, ho will find the positions of the 

 planets with considerable facility. Saturn is now a most interest- 

 ing object, as his ring continues very slowly to open. The observer 

 may scrutinise him with the highest power at his disposal. It is 

 Olid, and not very cxjilicable, that this planet bears magnification 

 notably bettor than its much more brilliant neighbour Jupiter. To- 

 night, and for the next fortnight, Saturn will be found a little to 

 the south-east of c Arietis. Jupiter, to the north-east of ? Tanri, 

 is by far the most striking object in the sky ; and will actually cast 

 a shadow of any body interposed between him and a white 

 surface. The now rapidly-fading great red spot and the white 

 spot on his equatorial belt will claim the observer's atten- 

 tion. His first satellite will cross his disc this evening, 

 itself entering on to it at 5h. .TOm. ; while at 5 h. 31m. its 

 shadow will follow it on to Jupiter's face. At 7 h. 18 m. the 

 satellite will pass off, followed by the sh.idow at 7 h. 47 m. The 

 same satellite will again exhibit a similar setpience of phenomena 

 on the 12th and early morning of the 13th, when they will happen 

 at 12 h. 22 m. p.m., 12 h. 57 m. p.m., 2 h. 37 m. a.m., and 3 h. 13 ra. 

 a.m. respectively. The student m\\ note that Jupiter, haviug 

 passed opposition, the satellites precede their shadows in crossing 

 his disc. Before opposition the shadows were the first to enter on 

 to his face. Prior to the transit of Satellite I. on the 10th, Satel- 

 lite II. will have passed across J npiter. Its ingress will occur at 

 5 h. 12 m. p.m., and that of its shadow at 6h. 21m. p.m. The 

 egress of the satellite happens at 7 h. 5G m. p.m. ; the egress of the 

 shadow at 9 h. 7 m. p.m. The observer should carefully watch this 

 phenomenon, since the shadow of this satellite has been seen of a 

 chocolate or brown colour on Jupiter's disc, while that of Satellite I. 

 has simultaneously appeared like a dot of ink. On the 11th 

 Satellite I. will bo occulted (i.e., will pass behind Jupiter's disc) at 

 9 h. 30 m. p.m., as will Satellite III. at 10 h. 41 m. p.m.; at 

 19 m. 59 s. after midnight the first satellite will reappear, not 

 from behind Jupiter's disc, but from eclipse in his shadow, a little 

 to the right of and below the centre of his follo\ving limb (as seen 

 in an inverting telescope). It will reappear at the same place from 

 eclipse, at the much more convenient hour of Gh. 48 m. 44s. p.m. 

 on the 13th. 



As the moon pursues her monthly path through the sky, she, of 

 course, passes in front of numerous stars, and as it is technically 

 said. *'occults" them. The disappearance andreappearanceof a star 

 at the moon's limb is a most interesting and curious occurrence, and 

 we propose, in conclusion, to give the times at which some of those 

 jihenomena will be observable during the next fortnight. As the 

 moon travels from right to left, of course, it is always her eastern 

 limb at which a star disappears, and her western one at which it 

 comes into sight again. Between new moon and full moon, how- 

 ever, this eastern limb is unilluminated, so that the star is ex- 

 tinguished with a suddenness that is quite startling. There is a 

 conventional way of representing the points on the moon's limb at 

 wliich disappearances and reappearances take place. It is this. A 

 great circle is supposed to pass through the zenith and through the 

 moon's centre, and the place where this circle cuts the apparent 

 upper part of her limb (as seen in an inverting telescope), but what 

 in reality, is her lowest point — this so-called "Vertex," we say 

 — is taken as the initial point, and angles arc measured towards 

 the right hand round her circumference as seen in an inverting 

 telescope. We may illustrate this by the aid of a florin, which we 

 must turn as if it were upside down for the purpose ; or, in other 

 words, invert the legend. Then, supposing this to represent the 

 moon as seen in an inverting telescope, a star occulted at any angle 

 of 133° from the vertex will disappear at a point in the circum- 

 ference between the "O" and the *'n" in the word "One," and 

 should it reappear at an angle of 327° will emerge opposite the " a " 

 in the sentence " of a pound." With this preliminary explanation 

 we may say that on the 11th r' Capricorni, a 4^ mag. star will dis- 

 appear at the moon's dark limb at C h. 6 m. p.m., at an angle of 90° 

 from her vertex, and reappear at her bright limb, at an angle of 

 25°, at 6 h. 39 m. p.m. On the 12th, the 5th mag. star k Aqnarii 

 will disappear at the dark limb at 4 h. 52 m. p.m., at an angle from 

 the vertex of 13.3°, and reappear at the bright one at Oh.Om. p.m., 

 at an angle of 327°. Occultations of 15 Piscium, 29 Arietis, and 

 B. A. C, 1651, will occur on the evening of the 13th, early morning 



