96 



NATURE 



[Nov. 30, 1876 



OUR BOOK SHELF 



British Manufacturing Industries.— ^.dSa^^ by G. Phillips 

 Bevan, F.G.S. " Jewellery," by George Wallis ; "Gold 

 Working," by Rev. C. Boutell ; " Watches and Clocks," 

 by F. J. Britten ; " Musical Instruments," by E. F. 

 Rimbault, LL.D. ; " Cutlery," by F. Callis. (London : 

 Stanford, 1876.) 

 This little volume (which is intended for popular read- 

 ing) is comprised of several short essays, by different 

 writers, upon the separate subjects indicated. Each 

 essay contains a fairly good account of the history 

 and general trade position of its subjects, but so far as 

 their mechanical construction and the manufacturing 

 operations involved therein are concerned, all are more 

 or less disappointing. No doubt this is in great m.easure 

 to be attributed to the nearly entire absence of diagrams, 

 the essay on watches and clocks alone being illustrated, 

 and that but scantily. Naturally some subjects suffer 

 more than others. In jewellery, gold working, and 

 cutlery the forms produced are familiar, the tools em- 

 ployed are simple, and what is the method of shaping 

 and fitting tOj;ether the various portions can easily be 

 imagined. But with musical instruments and watches 

 and clocks the case is different ; people, a priori, are 

 unacquainted with the apparatus or mechanism made use 

 of, and a free reference to diagrams or figures becomes 

 indispensable. In the essays upon jewellery and gold 

 working, especially in the latter, their aspects and 

 bearings as branches and developments of art are parti- 

 cularly dwelt upon. Cutlery, of course, is treated as an 

 industry, so are watches and clocks. We are afraid the 

 last-mentioned essay is not very carefully written, the 

 writer, amongst other things, actually forgetting to tell us 

 that there is any connection between the length of a 

 pendulum and the time of its swing. And what he can 

 be thinking of to describe Huyghens as a " French clock- 

 maker of eminence," who "about 1650 showed great 

 skill and ingenuity in arranging pendulums to clocks, so 

 as to describe a cycloid," we do not know. The essay 

 upon musical instruments (considering its not being 

 illustrated) is much more intelligible than it might have 

 been. 



The book is neatly bound and printed, but will require 

 considerable alteration and extension before it becomes 

 what from its title we expected to find it. 



An Introduction to the Osteology of the Mammalia. By 

 Prof. W. H. Flower, F.R.S. 2nd Edition. (London : 

 Macmillan and Co., 1876.) 



Prof. Flower's valuable " Osteology of the Mammalia " 

 holds so high a position among scientific manuals that 

 the appearance of a second edition requires but a passing 

 notice from us. The author is himself so continually 

 adding to our knowledge of the anatomy of the higher 

 Vertebrata, at the same time keeping fully au courant with 

 the investigations of both British and foreign zoologists, 

 that there are several minor additions which he has 

 had to make after an interval of six years, since the 

 appearance of the volume originally. Amongst the most 

 important of these, we notice the record of the conical 

 form of the odontoid process of the axis vertebra in the 

 Chevrotains {Tragulina), the introduction of a summary 

 of Prof. Parker's study of the development of the skull of 

 the pig, the account of the hyoid bones of the Ant-eater, 

 of the large pectineal process in Phyllorhine Bats, and of 

 the peculiarly anchylosed tarsus in the Muntjacs. In the 

 first edition the typography and the printing of the wood- 

 cuts was too black throughout ; in the new one this de- 

 fect has been entirely removed, both the type and the 

 figures being all that can be desired. There is a new 

 outline diagram of special interest introduced to illustrate 

 the mutual relations of the various elements of what 

 may be termed the typical mammalian skull. This re- 



places a plan drawn out for a similar purpose in which 

 the names of the bones were distributed over a page in 

 such a way as to indicate their relative positions. In the 

 new diagram the employment of outlines to the bones 

 renders the exact situation much more distinct and 

 enables the commencing student to carry away with him 

 a much more precise idea of the exact neighbourhood of 

 each part of each bone than was possible from the older 

 plan. We welcome with much pleasure this new edition 

 of the " Osteology of the Mammalia." 



LETTERS TO THE EDITOR 



\Thc Editor does not hold himself responsible for opinions expressed 

 by his correspondents. Neither can he undei-take to return, 

 or to correspond with the writers of, rejected mannscripts. 

 No notice is taken of anonymous communications i\ 



On the word " Force " 



Prof. Tait in his lecture on Force said that this word must 

 be used in a certain definite sense and in this sense only. In 

 ord( r to claim Newton's authority for the one definite sense to 

 which he would confine the word, he has to assume, not only that 

 Newton translated 7^r<r^ by vis impressa, but that he — an English- 

 man writing in Latin — used vis insita, vis matrix, &c., without 

 any English equivalents. Until good evidence for these assump- 

 tions—improbable as they are on the face of them — is brought 

 forward, Prof. Tait cannot claim the authority of Newton in /lis 

 favour. 



In the communication I made to Nature (vol. xv. p. 8) I con- 

 tended that the authority of Newton was against the restriction of 

 the word to this one sense, on the assumption that the equivalent 

 of Newton's word vis is foice. To those who demur to this 

 assumption I propose the questions : (i) Is it likely that Newton 

 had in his mind no English equivalents for vis insita, vis gravi- 

 tatis, vis centrifuga ? (2) If force is not English for vis, what 

 English word had Newton in his mind ? Until some new light 

 is thrown on these questions I maintain that Newton's authority 

 is claimed for the restriction of force to the sense of vis impressa 

 on, to say the least, insufficient grounds ; and that the obvious 

 interpretation of Newton's words is dead against it. 



I have, I hope, in a previous communication done justice to 

 Prot^ Tait's zeal for definiteness and accuracy ; and with him I 

 feel what supreme virtues these are in a scientific man. But I 

 contend that the wide sense of the wordi force — which I attribute 

 to Newton — is not loose and inaccurate ; it is simply general and 

 comprehensive ; each of the narrower uses, as in vis impressa, 

 vis insita, is not more accurate but more special : these special 

 senses are not inconsistent, though they are not identical ; they 

 are neither inconsistent with each other nor with the use of the 

 word force in its widest sense. Some English mathematicians 

 wish to have this valuable word all to themselves for a 

 special technical sense ; Newton claims no such monopoly, nor 

 is it claimed by all foreign mathematicians, nor conceded by 

 metaphysicians ; nor is the claim to this monopoly likely to be 

 conceded until a better title to it has been shown. 



Cambridge, November 24 P. T, Main 



Peripatus N. Zealandiae 



In the November number of the Annals and Magazine of 

 Natural History is a paper by Capt. Huttoa on Peripatus N. 

 Zealandla;, in which the author comes to the astounding results 

 that this species is hermaphrodite, and that its horny jaws are not 

 foot jaws but homologous with those of annelids such as Eunice. 

 If such w-ere in reality the case much of my results concerning 

 Peripatus capensis {P/iil. Trans. R. Sac, 1874, vol. clxiv. Parts) 

 would lose its value, and since I believe Peripatus to be a most 

 important form, and a representative of the ancestral stock of all 

 tracheates, in fact of the Protracheata of Prof. Haeckel, I hasten 

 to write a few words in reply. 



I obtained specimens of Peripatus N. Zealatidice at Wellington 

 from Mr. W. T. L. Travers, who has done so much for science 

 in New Zealand, and who most kindly assisted me and my late 

 colleague, R. von Willemoes-Suhm, in many ways, and who 

 first pointed out P. N. Zealandice to Capt. Hutton also. I 

 had further at least fifty specimens of Peripatus collected for 

 me and brought to me alive. I examined these and made 

 notes, but have been prevented by other work from publishing 



