540 



NA TUKE 



[October 6, 1892 



of large leading coupled wheels ; many engines were 

 running in India of this design before Mr. Stroudley 

 adopted it, and the whole question can be narrowed down 

 to the comparative life of tyres under different types of 

 engines ; there can be no doubt that a four-wheeled bogie 

 or a BiSsel truck in front saves the tyres of the leading 

 coupled wheels, a larger mileage being obtained from 

 them before they require to be returned. 



Chapter V. includes a description of the sand blast 

 arrangement for sanding the rails to prevent the slipping 

 of the driving wheels. This apparatus, small as it is, 

 has left its mark on the design of express locomotives. 

 The single engine has again come to the front for express 

 work with marked success, the latest design of Midland 

 and Caledonian engines being examples. 



This volume taken as a whole is most interesting, 

 and should be of value to all connected with the railway 

 system of this country as a book of reference. 



N. J. LOCKYER. 



OUR BOOK SHELF. 



Sketches of British Insects. By Rev. W. Houghton, 

 M.A., F.L.S., M.S.L. (London : O. Newmann and 

 Co., 1892.) 

 It is satisfactory to find that there is sufficient demand 

 for elementary books on entomology to render necessary 

 a new edition of Mr. Houghton's " Sketches of British 

 Insects ;" and for those who, as dwellers in the country, 

 wish to gain some insight into the insect life around them 

 few better books could be found. The differences between 

 the several orders of insects and the main distinctions of 

 the families are plainly and intelligibly set forth, though 

 in a few instances the definition of terms and sections is 

 somewhat faulty ; thus, "Arthropod" would be more fitly 

 translated " with jointed feet" instead of " with feet at the 

 joints," and the numerous exceptions are not enough in- 

 sisted on, there being for instance many insects with 

 aquatic respiration and Crustacea with aerial. In Lepi- 

 doptera the tongue is often completely absent, whilst in 

 butterflies the forelegs are never wanting, as stated, 

 though in certain families they are rudimentary in both 

 sexes or in the male only, and again the two pairs of 

 spurs on the hind tibiae are present in the vast majority 

 of moths and also in many skippers. . The insects se- 

 lected for description are well chosen, either as being 

 conspicuous and typical of their families or as illustrating 

 by their peculiarities some principle of adaptation to 

 surroundings, though in many cases the classification is 

 not according to modern ideas ; thus, the clearwings 

 {Sesia,^z) have no affinities with thebeehawks {Hemaris), 

 which belong to the Sphinges ; and the snouts {Hypcna) 

 are Noctues not Pyrals. The account in the Introduc- 

 tion of the structure and metamorphoses is especially 

 simple and clear, and the small volume is on the whole 

 an admirable sketch of British insect life, though the 

 coloration of the plates might have been made much 

 less crude without adding materially to the cost of pro- 

 duction. 



The Birds of Lancashire. By F. S. Mitchell. Second 

 Edition. Revised and Annotated by Howard Saunders. 

 (London : Gurney and Jackson, 1892.) 



We are glad to welcome a new edition of this book, 

 which we reviewed shortly after the publication of the 

 first edition Nature, vol. xxxii. p. 241). The task 

 of preparing a new edition (in the absence of Mr. 

 NO. 1 197. VOL. 46] 



Mitchell from England) was undertaken by Mr. 

 Howard Saunders, and it is scarcely necessary to say that 

 he has discharged his duty thoroughly. He has no per- 

 sonal connection with Lancashire, but he has had much 

 help from local authorities, especially from Mr. R. J. 

 Howard, of Blackburn ; and with their aid he has 

 brought the book, as far practicable, up to date. Several 

 species have been added to the list, and there is a new 

 index. 



Borneo : Its Geology and Mineral Resources. By Theo- 

 dor Posewitz. Translated from the German by 

 Frederick H. Hatch. (London : Edward Stanford, 

 1892.) 



The original work, of which this is a translation, has 

 been reviewed in Nature (vol. xl. p. 49), so that it is un- 

 necessary now to do more than record the fact that an 

 English rendering of the book has been published. 

 Dr. Hatch has done his work most conscientiously, and 

 the translation is likely to be much appreciated by stu- 

 dents of geology and mineralogy, and by all who have any 

 reason for being specially interested in the material re- 

 sources of Borneo. 



LETTERS TO THE EDITOR. 



[Tne Editor does not hold himself responsible for opinions ex- 

 pressed by his correspondents. Neither can he undertake 

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

 manuscripts intended for this or any other part oj Naturk. 

 No notice is taken of anonymous communications.^ 



"A New Course of Chemical Instruction." 



I AM much interested in the article in Nature for September 

 29, entitled "A New Course of Chemical Instruction," es- 

 pecially as the writer, in the criticism of the book in question, 

 whilst thinking that the method there advocated has theoreti- 

 cally more to recommend it than any other, doubts whether 

 practically the time required is not an insurmountable obstacle. 



For four years I have been able to teach beginners in Chem- 

 istry on a method very closely allied to the one here proposed, 

 that is to say, one in which no experiment is performed without 

 a definite object in view — the final object being the solution of 

 a given problem and no idea being given to the pupil of what 

 the result will be, and I am glad to be able to say that the time 

 required is not such a serious drawback as might be supposed, 

 whilst the intense interest aroused and the training in scientific 

 methods of work amply compensate for the slower acquirement 

 of chemical facts. 



I have not the advantage cf being acquainted with Mr. Cas- 

 tell-Evans' book, so that I am not quite sure how nearly my work 

 would agree with his course, but the fundamental principle is 

 undoubtedly the same, and is the one laid down by Dr. Arm- 

 strong in the report of the British Association Committee on 

 Chemical Teaching, where he advocates the teaching of Chemi- 

 cal method rather than Chemical facts. 



What generally appals the beginner in Chemistry is the mul- 

 titude of facts to be renumbered ; it .'•eems a mere question of 

 memory, and in consequence so dull and uninteresting, that the 

 explosion or " burst up " is the one point to be looked forward 

 to in the lesson. By this new method the pupils themselves are 

 put into the position of discoverers, they know why they are at 

 work, what it is they want to discover, and as one experiment 

 after another adds a new link to the chain of evidence which is 

 solving their problem, their interest grows so rapidly, that I have 

 seen at a demonstration lesson a whole class rise to their feet 

 with excitement when the final touch was being put to the 

 problem which it had taken them three or four lessons to solve. 

 Facts learned with so much interest are not forgotten and form 

 a solid basis which it is true is slowly laid, especially at first, 

 but it is interesting to see how much more quickly and easily 

 later facts are assimilated, each one fitting itself in with the 

 knowledge already acquired, and even when it becomes a ques- 



