December 1, 1887.] 



♦ KNO'WLEDGE ♦ 



the wind, she is practically sailing 45 degrees or four points 

 from the effective wind resulting from the combination of 

 her own speed with the winds. If her speed is iacreased, 

 she is sailing closer to the effective wind. But an ice yacht, 

 which makes no way, and is little resisted bj' friction, can 

 sail much closer than four points to the effective wind — in 

 other words, her velocity will continue to increase long after 

 she has attained a velocity equal to the wind's. 



Unfinished Worlds. By S. H. Paekes, F.R.A.S., F.L.S. 

 (London : Hodder & Stoughton. 18S7.) — It is not, at first 

 sight, very easy to see the raison J 'etre of Mr. Parkes's 

 volume, inasmuch as he simply reproduces (not even always 

 correctly) facts to be found in every modern work on popular 

 astronomy extant. The most apparently obvious motive 

 underlying his work would seem to be that of bolstering up 

 Su- J. W. Dawson's weak and inept attempt to disprove the 

 antiquity of man on the earth. But, having said this, we 

 must in candour add that our author describes the objects of 

 which he treats picturesquely enough, and that the perusal 

 of his book by those approaching the consideration of its 

 subject for the first time will be very likely to implant or 

 stimulate in them a taste for the study of the heavens. 

 We have said that 3Ir. Parkes is not always correct 

 in his reproductions of astronomical facts, in Ulustra- 

 tration of which assertion we may quote his dictum on 

 page 31, that it is " not determined whether the stars 

 making up the galactic region are arranged in the form of a 

 ring, with our sun and his planets in the centre," the fact 

 being that it has been incontestably proved that by no possi- 

 bility can such structure account for observed appearances. 

 He is seemingly familiar with Herschel's first diagram, and 

 knows nothing of what has been done since. Again, we 

 should like to know when — and by whom — the supposition 

 of the variability of Algol was found to be inconsistent with 

 that of the revolution of a large dark planet round it, as stated 

 on page 40. Further, he ought to be aware that the supposed 

 determinations of the axial inclination of Yenus to the 

 plane of her orbit are worthless; and, moreover, that a 

 dense atmosphere would keep in the heat like a blanket 

 and not suffer it to radiate into space as he imagines on 

 page 74. And yet again, what in the world does he 

 mean by Mars coming into '•partial opposition (I) . . . 

 about every two years " ? The synodical period of that 

 planet either is, or is not, 779'82 days. He should read 

 up the technical meaning of opposition in any standard 

 work on astronomy. He might as sensibly talk of partial 

 nothingness. Into his teleological argument it is wholly 

 needless that we should follow him ; though we may 

 perhaps point out that on page 223, among other places, he 

 muddles up Darwin's theo»y with Lamarck's. Has he ever 

 opened "The Origin of Hpecies"] Students of celestial physics 

 will be cui ious to know how and when Dr. Huggins (with 

 Dr. W. A. ]\Iiller at his elbow) ever had to ask Dr. 

 Frankland and IMr. Lockyer to corroborate his observations ; 

 while astronomers will laugh outright to find the last- 

 named gentleman's name quoted as that of an authority, 

 in company with those of 8ir William Thomson (not 

 Thom^json, as Mr. Parkes calls him), and Professors Young 

 and Langley, on page 62. 



Aslronomicnl RevJ/ttions. (London: E. Dexter. 1887.) — • 

 It is difiicult to enter into the feelings of a man who, 

 knowing nothing whatever of his .subject, sets himself calmly 

 to dogmatise upon matters of scientific fact of whose true 

 nature and bearings he is in the most profound ignorance. 



and who claims to teach that of which he has not himself 

 the most distant glimmering. Of the supernal conceit of 

 the anonymous author of the mass of rubbish whose title 

 heads this notice some idea may be formed from the 

 peroration of his first chapter, in which he has bean 

 asserting that the precession of the equinoxes is caused 

 by the trade winds blowing the earth round Mi " And 

 thus," he says, " more than two thousand years after 

 the discovery of the phenomenon by Hipparchus, the 

 true physical cause of the precession of the equinoctial 

 points now, for the firsc time, stands revealed to the human 

 intellect." Eeally the idea underlying this explanation (1) 

 is delightful. The gentleman who lifted himself by the 

 waistband of his own trowsers — to employ a current col- 

 loquialism — " wa.sn't in it " with our author. Pending his 

 purchase, and study, of some shilling book on mechanics, 

 we would suggest a simple experiment to him. It is to take 

 a pair of bellows into a sailing boat, and see how fast he 

 can drive her along by their aid. In Chapter II. the 

 secular acceleration of the moon's mean motion is traced to 

 " the earth's rotatory motion round the axis of the ecliptic." 

 In Chapter III. we learn that the diminution of the 

 obliquity of the ecliptic will continue until it and the plane of 

 the equator coincide I Chapter lY. shows that there is no 

 such a thing as aberration ; in fact, that Bradley was a 

 mere idiot. It is the deviation of the plumb-line that 

 causes what we call aberration! ^wt finis coronal opus, 

 and, just as schoolboys save up a piece of crackling or fat for 

 the last, so has our author reserved his choicest revelation 

 for his concluding chapter. The Hersehels — father and son 

 — Miidler, Struve, Proctor, and others have fondly theorised 

 on the constitution and structure of oar stellar surround- 

 ings, on the assumption that the fixed stars are (practically) 

 infinitely distant suns like our own. Not a bit of it ! 

 " The sun, which occupies the centre of our solar system, is 

 the only visible self-luminous body at present existing in 

 the celestial spaces." We are surrounded by a concave 

 sphere of land and water, from the internal surface of which 

 this sun is reflected hundreds and thousands of times (of 

 course only from the water). But, as in the case of the 

 earth, what is now land may in time become water, and vice 

 versd, so that when a fresh bit of the concave becomes 

 watery enough to reflect our sun, a new star appears ! We 

 feel that an apology is due to our readers for wasting even 

 the space we have done over such utter, irredeemable trash 

 as this ; but (always assuming that the writer of it is 

 responsible for his actions) no denunciation can be too 

 severe of any one of his intellectual calibre who presumes 

 to teach that of which he knows less than nothing. His 

 fan-ago of nonsense is beautifully printed and bound. 



Seven the Sacred Number. By Eichahd Samuell. 

 (London : Kegan Paul, Trench, k Co. 1887.) — Reflecting 

 on the shortness of human lite, there is something terribly 

 saddening in the thought of the awful waste of time of 

 which the author has been guilty in the compilation of the 

 astonLshing mass of puerilities which make up the volume 

 before us. He suflfers from what we may call septemania, 

 in the most virulent form. Everything (he fancies) — or 

 nearly everything — in the Bible is septenary in its arrange- 

 ment or signification, or both ; and when it is not, Mr. 

 Samuell insists that it ought to be, and punctuates, re- 

 divides, alters, or otherwis3 juggles with the text in order 

 to make it so. The amount of the most perverse ingenuity 

 he exhibits in his exegetic ramblings is marvellous. He ha.s, 

 moreover, the most supernal contempt for Biblical critics 

 who differ with him, and pooh-poohs poor creatures like 

 Westcott and Hort without mercy when their interpreta- 

 tion of a pas.sage clashes with his own heptadic tomfoolery. 

 Leaving, however, his work in its more purely theological 



