I40 



NATURE 



\yune 20, 1872 



OUR BOOK SHELF 



Meibaucr's Phvsiuiic Dcscltaffcnhcil dcs Sonnensysli'ins. 



(Berlin : Cai'l Habel.) 

 This is a second and freshly-arranged edition of a com- 

 prehensive little treatise on the nature of the solar system. 

 It requires no great acquaintance with the present state 

 of science to vindicate the accuracy of the author's pre- 

 liminary remark, as to the difficulty that students ex- 

 perience from the wide dispersion of modern observations 

 among heterogeneous memoirs and journals in various 

 languages, and the necessity of a large library and 

 abundance of leisure ; and it is impossible not to ap- 

 preciate his attempt to combine these scattered materials 

 in a condensed and accessible form. Nor can it be 

 doubted that a considerable amount of labour has been 

 devoted to the work, which has been made attractive by 

 perspicuity of treatment and facility of style, as well as 

 by occasional ingenuity in hypothesis. Yet the execution 

 cannot be said to correspond with the excellency of the 

 design ; and the deficiency, more apparent perhaps to our 

 own minds than to those of Continental readers, is such 

 as necessarily results from one-sided and imperfect views. 

 The eternity of matter, an idea to many minds especially 

 and utterly abhorrent, should not, to say the least of it, have 

 been assumed ; and other less objectionable hypothesesand 

 statements are adopted, which may not be as incontro- 

 vertible as unwary readers will be led to suppose. No 

 doubt the author, in employing as part of his motto the 

 words of Uarvvin, " False facts are highly injurious to the 

 cause of science," was quite unconscious that the result of 

 an inquiry into some of his own facts (or rather assertions) 

 would not be quite satisfactory. But we do not know 

 what to make of such statements as these— that Priestley 

 called his vital air (oxygen) by the name of Phlogiston— 

 that Huggins found in the nuclei of comets the lines of 

 nitrogen, hydrogen, and carbon siinilar to those given by 

 the Geissler tubes— that there are two bright lines in the 

 spectrum of Sirius, one of which is displaced by the star's 

 movement — that the red, green, and yellow tints of the 

 aurora never lose their relative positions ; that the force 

 of gravity at the upper limit of the atmosphere may be 

 considered not materially different from that on the earth's 

 surface, while the centrifugal (tangential) force perceptibly 

 increases. Nothing but an unkind, or bitter, or self- 

 ignorant spirit would refuse to leave a fairly broad margin 

 for inevitable human imperfection ; but it must be a very 

 large paper copy indeed that would find room for state- 

 ments such as these. Nor is it easy to understand why 

 Lockycr's just claim should have been ignored to an equal 

 share with Janssen in the grand discovery of prominences 

 round the uneclipsed sun ; or why discredit should have 

 been thrown upon the connection of the solar-spot maxi- 

 mum with Sabine's magnetic period, or the planetary one 

 established by the Kew observers. Other omissions might 

 be pointed out, and the work would have been greatly im- 

 proved by a discussion of the effects of temperature and 

 pressure in modifying elementary spectra— a branch of 

 inquiry to which allusion has barely been made, but which 

 is of essential importance in spectrum analysis, and the 

 fuller development of which alone, perhaps, promises a 

 more satisfactory solution of many cosmical phenomena. 

 But while it appeared a matter of duty to mention these 

 deficiencies, we must add, in all fairness, and with greater 

 pleasure, that some of his theories are very interesting and 

 well handled ; such as that in which he would account for 

 the eruption of the protuberances by the unstable condi- 

 tion of gaseous matter on the confines of lluidity, dis- 

 covered by Andrews and Thomson ; or that of the un- 

 limited extension through space of the planetary atmo- 

 spheres in extreme tenuity ; and there is much ingenuity, 

 at any rate, in the idea of accounting for the variations of 

 atmospheric pressure and electricity between the tropics 

 by the resistance, however infinitesimal, which our globe 



sustains in its rapid passage through a space to which 

 neither Newton nor Laplace ascribed absolute vacuity. 

 The curious inconsistency with which, as a denier of 

 equivocal generation, he calls in the germs of terrestrial 

 vegetation from external space, where they have been 

 educed under certain conditions of temperature, pressure, 

 andtime,is but a specimen of the difficulties to which every 

 hypothesis is subject, that ignores tlie existence of an 

 omnipotent will ; but there are some who will look with 1 



amusement, and some few with a warmer feeling, at his I 



vigorous onslaught on the idea of a luminiferous aether; I' 



concluding with the keen remark, that to prove the 

 existence of such an :\;lhcr, recourse is had in turn to the 

 very phenomena which it was invented to explain. 



T. W. W. 



Knapsack Manual for Sportsmen on the Field. By 



Edwin Ward. (Bradbury and Evans, 1S72.) 

 One who has come so much in contact with sportsmen 

 as Mr. Ward must have done should surely know that 

 men do not go out with knapsacks when intent on killing 

 big game. The title " Knapsack Manual " is most unfor- li 

 tunate. Moreover, if the book is intended for sportsmen \ 

 on the field, why should a considerable portion of it be <( 



given up to the mode of setting up a tiger, which a sports- ' 



man is very unlikely to do for himself, and certainly would 

 not attempt in the field ? Mr. Ward, though he seems to 

 have considerable regard for artistic treatment and com- 

 patibility in the setting up of skins, would yet appear to 

 put lichens with his stuffed birds in the conventional 

 style. What a relief to the eye it would be to see 

 a case of stuffed birds without a particle of dead 

 wood or lichens in it ! The directions given for 

 skinning and preserving specimens are not full enough ; 

 there are better works on the subject in existence. 

 The lists of game to be found in various parts of the 

 world, at the commencement, form the most useful part 

 of the book. The account of a Museum of Natural His- 

 tory of the Earth from man to a granite stone contained 

 in a case loft. long by 7 ft. high, displays a lamentable 

 amount of ignorance. Some of the remarks about the 

 various creatures are very amusing, as, " Gasteropoda 

 proceed by the belly." "Armadillos are very remarkably 

 swift in flight." Altogether this book appears to be of the t 

 nature of an advertisement, and we think a not very sue- I 

 cessful one. < 



LETTERS TO THE EDITOR 



[ The Editor docs nol hold himself responsible for opinions expressen 

 by his correspondents. No notice is taken of anonymous 

 communieations. ] 



The Method of Least Squares 



I.N the number of Nature for June 6, Prof Asaph Hall, of 

 Washington Observatoiy, called attention to what he regards as 

 a singular oversight in the history of this subject, viz., that in 

 1 770-1773 Lagrange pubhshed an elaborate memoir at Turin 

 under the title " Mc-moire sur I'utilite de la Methode de prendre 

 le Milieu entre les resultats de plusieurs Observations, &c. " 

 T'lof Hall remarks that the only notice of this memoir he has 

 seen is contained in the Berliner Jahrbiieh for 1S53, and tliat in 

 the abstract of a memoir of mine on the subject in the notices 

 of the Royal Astronomical Society for April 1S72, the name of 

 Lagrange does not appear. 



As regards myself, I need only state that Lagrange's memoir, 

 as well as Simpson's, is referred to in my paper ; although, as no 

 examination is made of it there, the name is omitted in the 

 Abstract, where reference is only made to tlie authors of investi- 

 gations in which an attempt is made to prove either the law of 

 facility or the method of least squares, and which were therefore 

 referred to with more or less detail in the paper itself 



Further, I should not regard it as an omission if in the history 

 of Least Squares no mention was made of Lagrange ; in fact, 



