110 



KNOWLEDGE 



[May 1, 1896. 



we are not weariocl in the one before us with minute 

 descriptions of each day's march, and the book will prove 

 interesting reading to everyone. Beyond this it is full of 

 valuable information and shrewd conclusions bearing on 

 the natives, natural history, and general aspect of the 

 region traversed. The author seems to have been greatly 

 hampered by fever and other ills, and although the results 

 of the expedition are not startling, a considerable amount 

 of useful work has been done. The book is provided with 

 two maps — one, showing coflee zones and areas fit for 

 colonization, being particularly instructive. Although the 

 illustrations, which are taken from the author's photographs, 

 are not very successful as pictures, they are very useful in 

 showing the characteristics of the country. Altogether the 

 book is a valuable one, and especially so to naturalists and 

 those (and who is not '?) interested in Africa. 



Binis from Mnidmi and Klxt'iclniv. By Mrs. Hugh 

 Blackburn, (l^dinburgh : David Douglas.) Illustrated. 

 The illustrations occupy the bulk of this volume. They 

 have been exceedingly well reproduced from drawings 

 by the author, mostly from life. Some of ihe drawings 

 are excellent — perfectly natural and accurate — notal)ly 

 those of the tawny owl on page 28, and the guillemot on 

 page 102. A good many of the drawings, however, are 

 stiff and unnatural. Although limited, the text has con- 

 siderable value, as Mrs. Blackburn has written solely from 

 personal observation. Moreover, she has had many 

 opportunities for observing rare birds. These observations 

 have been faithfully recorded, and on this account the 

 book will prove of undoubted interest. 



The Structure and Bevehipmcnt of the ]\[()sses and Ferns. 

 By Prof. D. H. Campbell, Ph.D. (Macmillan.) Illus- 

 trated. 143. Within the past ten years a large number 

 of investigations have been made upon the structure and 

 development of the numerous plants included under the 

 name Arehegoniatffi. " The present work was undertaken," 

 says Prof. Campbell, " mainly for the purpose of presenting 

 in somewhat detailed form a resuwr of the substance of the 

 great mass of literature upon the subject which has accu- 

 mulated, and much of which is necessarily out of reach of 

 the many botanical workers who have not access to the 

 great libraries." The author himself has greatly assisted 

 in extending and improving the knowledge of the Arche- 

 goniates, and some of his papers form the basis of this 

 book, while the results of researches upon representatives 

 of most of the groups discussed are now published for the 

 first time. The book thus possesses the sterling ring 

 which results from personal observation, and is thereby 

 distinguished from mere compilations. IJotanists should 

 be grateful for this solid and comprehensive contribution 

 to the literature of the Archegoniate series — the best that 

 has appeared for some years. Prof. Campbell's work will 

 be long recognized as a standard one for students of the 

 structure, development, and inter-relationships of the lowly 

 but important families of plants described in it. 



Our Homehold Tn.iects. By Edward A. Butler, B.A., B.Sc. 

 (Longmans.) Illustrated. Mr. Butler's writing is too well 

 known to readers of Knowledge to need any eulogium on 

 our part. The book before us is an interesting series of 

 articles, which originally appeared in Knowledge, on the 

 insect pests found in dwelling-houses. Although the book 

 is mtended primarily for the novice, it will, no doubt, be 

 of considerable service to more advanced students of ento- 

 mology, because it brings together information which has 

 hitherto only existed in a scattered form. The illustrations, 

 which have been prepared from microscopical slides, are 

 excellent, and the book deserves every commendation. 



Bi/ Tanf/M Paths : Stray Leaves from Nature's Byewai/s. 

 By 11. Mead Briggs. (Warne.) Illustrated. Rather a 

 mixed collection of short essays is brought together in this 

 book. The author's style is quaint, and is rather suggestive 

 of " padding." But it is pleasing in parts, and although 

 the book will not bear close reading it makes a delightful 

 volume to skim through. Birds form the chief sulaject, 

 but the author makes frequent digressions and often strays 

 from "nature's byeways." 



Tlie Story of the Solar Si/stem. By George F. Chambers, 

 F.R.A.S. (George Nownes, Ltd.) "illustrated. Is. This 

 little book provides accurate and interesting reading on 

 planetary astronomy at a price within the reach of every- 

 one, and we trust that the publisher's enterprise and the 

 author's work will be rewarded by a large sale. ' 'Astronomy, 

 like charity," someone has said, "should begin at home " ; 

 and the remark has much to commend it. Therefore we 

 say to those persons who wish to commence the study of 

 astronomy. Procure this descriptive and practical accoimt 

 of the astronomical home-circle, and you will derive from 

 its perusal a sound foundation upon which to erect future 

 knowledge. We are glad to be able to state that the 

 illustrations in the present book are far better than those 

 of the companion volume, in which the " Story of the 

 Stars " is told. 



A Laboratory Course in Experimental Physics. By W. J. 

 Loudon, B.A., and J. C. McLennan, B.A. (Macmillan.) 

 Illustrated. 8s. Od. It may be possible to write a perfe.;t 

 book on experimental physics, but it has not as yet been 

 accomplished. It is, therefore, not invidious to say that in 

 this volume, which in many respects is well presented, 

 there exist blemishes which could have been avoided. The 

 book is divided into two courses, of jwhich the former deals 

 with instruments for measuring lines, hydrostatics, optics, 

 and heat in a very elementary way. The latter treats of 

 sound, of heat more fully, and of magnetism and electricity. 

 At the end there are short additions on gravity determina- 

 tion and on the Torsion Pendulum ; and, of course, there 

 are some tables borrowed in the usual way, and not 

 always transcribed with perfect accuracy. The chief fault 

 in the book is that, in spite of its title, it is written too 

 much from the theoretical standpoint. In the hydro- 

 static methods of determining specific gravities no instruc- 

 tion is conveyed on the important correction rendered 

 necessary by the buoyancy of the air, neither is anything 

 said about volume determinations by the hydrostatic balance. 

 But probably the optical portion of the book is the least 

 satisfactory. The use of the collimator in goniometrical 

 work seems to be quite misapprehended. The instructions 

 imply (and a figure actually supports this view) that only 

 a narrow beam of light issues from the lens, as from a 

 slit, for the student is told to carefully place the edge of 

 the prism accurately at the centre of the instrument. The 

 optics are, in fact, far from practical. But acoustics and 

 heat are handled more completely. The many practical 

 points which have actually to be attended to are either not 

 noticed at all or only in a very incomplete way. The authors, 

 however, make an observation in describing the determi- 

 nation of magnetic inclination from which the Kew 

 Committee of the Royal Society may derive illumination, 

 viz. ; that if the instrument is turned through two right 

 angles to eliminate certain errors for which that operation 

 is necessary, then other errors, for the correction of which 

 directions are given in the Kew system to reverse the 

 needle on its agate bearings, also disappear, so that this 

 latter operation really is waste of time. 



Consider the Heavens: a Popular Introduction to Astronomy. 

 By Mrs. W. S. Aldis. (The Rehgious Tract Society.) 

 Illustrated. 2s. 6d. " The heavens declare the glory of 



