148 



NA TURE 



[June 15, i«93 



of these and other counties in Scotland is consequently 

 thrown away. The railways and telegraphs of South 

 Africa are far behind the age, the Orange Free State being 

 shown as if still undisturbed by the engine's whistle. 

 The cable (p. 5) to the Cape by the west coast is only 

 partly shown, though correctly given in the German 

 original ; and the Bermudas are now in electrical touch 

 with the world, though this does not appear on the map. 

 There are surprisingly few errors of spelling, and for 

 the general purposes of the newspaper reader the atlas 

 is eminently serviceable. 



Only a few physical maps are given, including two 

 pages of familiar and rather feeble astronomical diagrams, 

 the use of which must be very slight. The world in 

 hemispheres is shown with an attempt at orographical 

 colourmg on the land, and there are bathymetrical charts 

 of the Atl.mtic and Pacific Oceans. The latter are some- 

 what remarkable. The contour lines of depth are given 

 as no, 1 100, 2200, 2750, and 3300 fathoms, those odd 

 numbers corresponding of course to even depths in metres, 

 but the occasional soundings dotted over the surface are 

 stated not in fatho ns, but in feer. Similarly the one 

 small climate map shows isotherms drawn to represent 

 centigrade degrees, but lettered with the approximate 

 Fahrenheit equivalents. The system of showing the 

 winds on this map is arbitrary, and the arrangement it 

 implies is unnatural. The physical maps might indeed 

 be excised without serious loss. 



The plan of printing the hill-shading — usually much 

 generalised — in brown, throws out the black lettering, 

 admirably, while the rivers and railways are very clearly 

 shown in most cases. The importance of clear maps in 

 following any movement or distribution cannot be over- 

 estimated, and the Switzerland (pp. 53, 54), Caucasus 

 (p. 71), and Greece (p. 72), in this atlas are beautiful 

 examples of artistic work, embodying ample detail with- 

 out confusion. 



OUR BOOK SHELF. 



Types of Animal Life. By St. George Mivart, F.R.S. 

 (London: Osgood, Mcllvaine and Co., 1893.) 



It is reported of a negro preacher that, having omitted 

 to note the source of his text, he counselled his hearers 

 to search diligently for it, assuring them that in doing so 

 they would find many other texts which would be for 

 their souls' good. We are reminded of this anecdote in 

 reading Prof. Mivart's new book on popular natural 

 history. In our search for the types given in the table of 

 contents we have been rewarded by finding a pleasing 

 description of a goodly number of the higher animals. At 

 the beginning of the fourth chapter we are told that the 

 bull-frog has been selected as one type of animal life in 

 order to introduce the group of Batrachia. Very little is 

 said, however, about the bull-frog himself, though there 

 is a figure of him in a deprecating attitude suggestive of 

 some appreciatioi) on the part of the artist of the some- 

 what shabby treatment this Batrachian elect has received. 

 But there is much interesting matter concerning am- 

 phibians of all kinds, illustrated by reference to, or short 

 descriptions of, some twenty genera. The first 

 chapter is headed "Monkeys"; and similar head- 

 ings would, we think, have been more appropriate 

 throughout. As it is, the animal named is, in each 

 case, merely a convenient starting-point for the considera- 

 tion of the group to which it belongs. We do not know 

 NO. 1233, VOL. 48] 



whether the chapters embodied in the book have already 

 done service in any form in America, but the animals 

 selected suggest that such may have been the case. We 

 have the opossum,the turkey, the bull-frog,the rattlesnake, 

 the Carolina bat, the American bison, the racoon, the 

 sloth, and the sea-lion ; while the chapter which deals 

 with, or starts with, the list-named animal begins thus : — 

 " The sea-lion is a beast the sight of which must be 

 familiar to very many Americans." The term "animal 

 life " of the title of the work is shown by the contents to 

 be applied to the dactylate vertebrata only, three-fourths 

 of the volume being devoted to mammals, or beasts as 

 the author prefers to call them. 



Unfortunately the proofs have been carelessly corrected, 

 so that misprints {e.g. fleshating beasts, p. 209), errors 

 of fact (e.g. that Notoryctes has recently been discovered 

 in America, p. 60), grammatical errors {e.g. only two 

 kinds of elephant now exists, p. 207) ; a redundant "and ' 

 before '■ which," p. 217), and inelegancies {e.g. python- 

 like headed reptiles, p. 149 : the blind worm is popularly 

 reported as being deadly poison, p. 146) have been 

 suffered to remain. Technical terms have, as far as 

 possible, been avoided ; but it is questionable whether 

 the use of such a term as " wing- wedge bone" is advis- 

 able. Surely those who can take in such names of pla:es 

 as " Eschscholtz Bay," and such local names of animals 

 as " Catamiztli," could swallow "alisphenoid" without 

 serious mental indigestion 



For the rest we have nothing but praise. A great deal 

 of information is conveyed in a pleasant style. The 

 illustrations, if not quite all that could be desired, are 

 decidedly above the average. The reiterated allusion to 

 the possibly independent origin of similar structures (or 

 the independent origin of different structures, as it 

 appears on p. 120) is, in our opinion, not out of place in 

 such a book. Those who enjoy a smattering of knowledge, 

 picked up from popular works, are apt to be so terribly 

 dogmatic that it is well to urge them to keep their minis 

 " free from prejudice and ready to receive all and any 

 truth which may be demonstrable.'' C. Ll. M. 



Science Teaching in Schools. By Dr. Henry Dyer. 

 (London: Blackie and Son, 1893.) 



An address given by Dr. Henry Dyer on science teaching 

 in schools has been amplified and is now published in 

 book form. The points dwelt upon appeil particularly to 

 the managers and teachers of existing elementary schools, 

 and of the secondary and technical schools now being 

 organised in all parts of the country. In an appendix 

 (which, by the way, is almost as long as the address itselO 

 are given syllabuses of elementary science as taught under 

 the London and Leicester School Boards, and the curricula 

 of the evening classes of the Glasgow and West of Scot- 

 land Technical College. A commendable feature is the 

 insertion of the courses of instruction at the Ecole de 

 Commerce et de Tissage of Lyons and the Public 

 Mercantile Educational Institute of Leipzig. 



LETTERS TO THE EDITOR. 



\_The Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

 to return, or to correspond with the writers of, rejected 

 manuscripts intended for this or any other part of Nature 

 No notice is taken of anony motes communications. ] 



Vectors and Quaternions. 

 Prof. Macfarlane claims that his " fundamental rules 

 for vectors are based on physical considerations, the prin- 

 cipal one of which is that the square of a vector is essentially 

 positive." His proof is virtually this : — The expression for the 

 kinetic energy {\ mv"-) is an essentially positive quantity. It 

 contains one factor ^m evidently positive. Hence the other 

 factor 2^- must also be positive. "But z; denotes the velocity 



