July 14, 1 881] 



NATURE 



235 



descriptions of such as possess special interest would 

 have been equally acceptable to amateurs generally. 



We are not disposed to criticise too closely a volume 

 involving a large expenditure of time and trouble for the 

 benefit of those who occupy their leisure evenings in tele- 

 scopic obsei'vations, but as the author expresses his desire 

 to receive corrections or suggestions for future editions of 

 his work, we will here refer to several defects which we 

 have remarked in a pretty careful examination of it, in 

 the hope that his attention may be directed to the kind of 

 revision by which another edition may be improved. 

 Some of the more remarkable objects appear to be treated 

 with unfortunate brevity ; we may instance the fine binary 

 star 6/ Eridani, of which a single epoch is given, without 

 mention of the orbit having been determined by Dr. 

 Doberck, or indeed any intimation that the star is in 

 rapid motion : the first elements were assigned by Jacob. 

 A still more noticeable case is that of a Centauri, one of 

 the most interesting objects in the heavens, which is dis- 

 posed of in half-a-dozen lines, without reference either to 

 the elaborate investigations of its annual parallax since 

 Henderson's time, to its large and well-established proper 

 motion, or to the numerous orbits which have been com- 

 puted, more especially those obtained since the passage 

 of the peri-astron by Dr. Doberck and Dr. Elkin. Only 

 two epochs are transcribed, one of them being the com- 

 paratively rough result of Gilliss at Santiago in 1851 ; in 

 no instance would it have been better worth while to 

 extract from the long series we possess, a sufficient 

 number of measures to enable the reader to judge of the 

 motion in the system. A very insufficient notice appears 

 of 2 518, a binary of which we may soon expect to have 

 approximate elements, and the case of y Coronas Australis 

 is quite misrepresented ; from the few epochs given at 

 p. 555, it might be inferred that there has been a direct 

 change in the angle of position of about 30' in forty-five 

 years, whereas there has been an actual nYr(;'_^;'(7<T't' motion 

 in the angle of nearly 160', upon which Schiaparelli 

 calculated elements which represent the latest measures 

 closely. Of the four cases where the author has appended 

 orbits, in three (Castor, f Cancri, and | Urs£e Majoris; 

 they are vitiated by typographical or other error. 



Kirch's variable star in Cygnus, which Mr. Chambers 

 calls x^ is the true x Cygni of Bayer, to which letter 

 Flamsteed's 17 Cygni has no claim; the cause of Flam- 

 steed's misnomer was explained by Argelander many 

 years since. The designation x" is calculated to add to 

 the doubt and confusion already existing as to this vari- 

 able, of which the author unwittingly affords an illustra- 

 tion. The position assigned for 1890 is not that of the 

 variable star (which is Lalande 37835), but is that of 

 Piazzi XIX. 295, wrongly identified with Kirch's star by 

 Piazzi, a circumstance to which, oddly enough, Mr. 

 Chambers alludes in his notes, warning his readers against 

 a mistake which he has himself just made. The correct 

 place of the variable for 1890 is in R.A. igh. 46m. 21s., 

 Decl. 32° 38'-2. 



The story of Cacciatore's supposed distant planet is left 

 where it was by Smyth, the later calculations of Valz and 

 Oeltzen, who showed that the motion indicated by Caccia- 

 tore could only apply to a minor planet, not being 

 mentioned ; and there are a number of other cases where 

 the information supplied has not been brought up to date. 



Mr. Chambers's volume has been handsomely printed 

 at the Clarendon Press, and includes, for a frontispiece, 

 the scale of colours, given by Smjth in his "Sidereal 

 Chromatics," with the view to assist observers, in judging 

 of the colours of the components of double stars. 



OUR BOOK SHELF 

 Botatiyfor Schools and Science Classes. By W. J. Browne, 



M.A., Lond., Inspector of National Schools. Second 



Edition, revised and enlarged. (Dubhn : Sullivan 



Brothers, 1881.) 

 Mr. Browne is the author of a variety of elementary 

 mathematical books. In preparing this little manual of 

 botany it may be presumed, therefore, that he has had to 

 struggle with the difficulties which must always beset the 

 amateur. The result resembles what one has often un- 

 fortunately met with in similar cases before. There is a 

 want of simplicity in the treatment, much that is un- 

 essential and unnecessary for students of any grade, 

 a good deal that is only of historical value, and what is 

 worse, not a little that is downright error. This is the 

 more unfortunate, as the questions at the end of the 

 chapters and the examination papers which fill the last 

 pages show that the book has a very definite aim. What, 

 however, it may be asked, is likely to happen to exa- 

 minees who reproduce such statements as the following? 

 " Coffee. — The fruit consists of two halves, nearly hemi- 

 spherical ; " or " Galls — excrescences on oak, produced by 

 an excretion thrown out round an egg deposited by an 

 insect" (p. 98). On p. 60 the beech is given as aftbrding 

 an example of a capsule in its fruit ; here the author has 

 confounded the involucre with a pericarp. On the same 

 page we find the following remark : " Around the seed 

 . . . there is often developed a quantity of albioncii, for 

 the nourishment of the seed during germination " ; on 

 p. 55, "The germinal vesicle soon develops into the 

 embryo or germ, containing the plantlet." This is on a 

 par with the account of the process of fertilisation on 

 p. 10, "A protoplasmic substance {fovilla) flows from 

 the pollen-grain into the ovule and ripens it, so that it 

 becomes a seed." The part of the book devoted to syste- 

 matic and descriptive botany is better, though often open 

 to criticism. If the writer had carefully studied Peni- 

 cillitim he would not have said, "The cells composing 

 the branches (Fig. 89) are spores or couidia" \ he has 

 apparently been misled by his Fig. 89, which might do 

 for one of the bog-oak ornaments sold in Dublin shops, 

 but is a very inadequate representation of Penicilliiim. 

 The examples of plant-descriptions are not sufficiently 

 full, and are sometimes obscure, as for instance when the 

 anthers of the common daisy are said to be "' simple at 

 base." The whole book still wants a thorough revision at 

 the hands of a competent teacher to make it a safe guide 

 for elementary students. 

 First Lessons in Practical Botany. By G. T. Bettany, 



M.A., B.Sc, F.L.S. (London: Macmillan and Co., 1881.) 

 This is an excellent little book. Its diligent study by 

 teachers as well as pupils would give descripti^-e botany 

 the real educational value which is so often claimed 

 for it, and at bottom it no doubt possesses, if only the 

 old type of manuals could be exterminated. What a 

 weight would be removed from examiners' minds if ex- 

 aminees would really take to heart Mr. Bettany's impres- 

 sive admonition (which should be hung in every examin- 

 ation room where plants are set for description) : — " Do 

 not suppose or imagine facts of structure which \ou cannot 

 verify." It is really refreshing to come upon a manual, 

 the object of which is to drill students in a healthy scien- 

 tific method, and not merely to teach them how to impose 

 on examiners with a show of sham and often preposterous 

 knowledge, which has but a temporary hold on the memory 

 and none on the understanding. The only genuine criti- 



