January 17, 1901] 



NATURE 



273 



grants being subject to the roads being kept in repair to 

 the satisfaction of the county justices. A further improve- 

 ment took place when these roads were taken over by 

 the County Councils. 



The bicycle has, however, been the main agent in 

 recent road improvement. To use these machines with 

 any comfort a road must be in thoroughly good order, 

 level, and free from loose stones and mud. The voice 

 of the bicyclist is heard everywhere calling out when 

 roads are in bad order, and local legislators are driven 

 both by their own experience and that of their constitu- 

 ents to bring about a better condition of the main roads 

 and highways. An institution known as the Roads Im- 

 provement Association has been formed, and, besides 

 bringing pressure to bear on the local authorities, has 

 issued a great quantity of literature for the guidance" of 

 local surveyors and roadmen as to the management of 

 the roads ; upwards of 13,000 pamphlets containing prac- 

 tical information on the management of roads have been 

 •distributed by this society. 



Fortunately road reformers are able to show, by con- 

 clusive evidence, that roads kept in thoroughly good 

 order cost less in annual maintenance than when they 

 are left to get rutty and uneven and covered with mud 

 or loose stones. 



Mr. Aitken's book is a good practical treatise on the 

 making and maintenance of roads. It is divided into 

 fifteen chapters, which deal respectively with the history 

 of road-making ; traction ; the construction of new roads ; 

 bridges, culverts and retaining walls ; road material ; 

 quarrying ; stone-breaking and haulage ; road-rolling 

 and scarifying ; paved roads, including wood, asphalt, 

 brick, and tar macadam ; footways, &c. 



The book deals principally with main roads and those 

 subject to heavy traffic, which, as a rule, are now under 

 the care of the county surveyors, who are skilled ex- 

 perts, and very little attention has been given to the 

 requirements of the ordinary highways, where improve- 

 ment is most required. The space devoted to quarry- 

 ing, which occupies no less than sixty-seven pages, or 

 about one-sixth of the whole book, could well have been 

 spared, as it is rarely in these days that a surveyor has 

 to quarry his own road material, and the space would 

 have been better devoted to showing how ordinary high- 

 ways may be maintained in good order and kept level 

 and clean, and material placed on them when required 

 without inconvenience to the traffic in situations where 

 steam road-rolling is impracticable. 



OUR BOOK SHELF. 



Knowledge, Belief and Certitude. By F. Storrs Turner. 

 Pp. viii -f 484. (London : Swan Sonnenschein and 

 Co., Ltd., 1900.) Price ^s. 6d. net. 



Mr. Storrs Turner distinguishes knowledge from 

 -consciousness as interpretation from datum. He alleges 

 as base of the former three certitudes, as to self, other 

 selves and real things. He finds the sciences to involve 

 the same pre-conditions and to take a permissibly ab- 

 stract point of view — that of a fictitious independent 

 spectator. But he holds that, therefore, the sciences 

 are not adequate to concrete reality, while the preten- 

 sion of science in general to present the whole is vain. 

 In psychology the standpoint of the ideal spectator is 



XO. 1629, VOL. 63 j 



inadmissible, and philosophy has failed because of the 

 same abstraction. But among concrete ends we find our 

 conviction as to some certain knowledge satisfied. Real 

 knowledge belongs to the teleological sphere. 



His conclusion to the failure of the speculative and 

 the success of the purposive reason surprised Mr. Turner 

 with the force of a revelation. The first chapters of his 

 inquiry, which " remain substantially as they were origin- 

 ally written," were committed to paper years ago when 

 " a dense fog " covered his mind. A trace of this is to 

 be found in the attempt to maintain concurrently that the 

 certitude of other selves is an inference of reason (p. 74), 

 that it is plamly one with the certitude of self (p. 89), and 

 that neither is able to come into existence apart from the 

 other (p. 95). Mr. Turner can say within a page that 

 " by real things we mean permanent things " (p. 80), and 

 that " what we have is the certitude that there are a 

 multitude of real things, some of them permanent, most 

 of them changing" (p. 81). It will perhaps be unneces- 

 sary to say that his verbal criticism on such writers as Mr. 

 F. H. Bradley depends for its validity on a hit or miss 

 principle. It is a little grotesque to have estimates of 

 Hegelian metaphysics and post-Hegelian logic from the 

 standpoint of "reflective common-sense, aware of its 

 limitations." Mr. Turner thinks that continuity implies 

 indivisibility, and his verdicts on much in philosophy 

 and science rest on similar misunderstandings. 



" Knowledge, Belief and Certitude" is, however, by no 

 means a worthless book. There is a certain dialectical 

 ability in much of it, and a tenacity as to main prin- 

 ciples which will appeal to the clear-headed reader who 

 can discount the fallacious element. It is, however, as 

 an honest attempt to think the problem of knowledge 

 right through, and to present a record of the process 

 as well as the results of his investigation, that it chiefly 

 commends itself. How and why Mr. Turner came to 

 his estimate of various views and systems, rather than 

 that estimate itself, is the thing worth studying. 



H. W. B. 



Notions de Mineralogie. Par A. F. Renard et F. Stober. 

 11™*' Fascicule ; Classification et Description des 

 Especes Minerales. Pp. 191 to 374. (Gand : Ad 

 Hoste, 1900.) 



The first fascicule of this text-book, containing the 

 general principles of mineralogy, has already been 

 noticed. The second fascicule (pp. 191-374) is devoted 

 to the detailed description of mineral species. A large 

 number of species are mentioned and, consequently, the 

 majority are only briefly treated ; in its mam features 

 the book necessarily resembles other mineralogical text- 

 books. 



It seems that, by a wise provision, all candidates in 

 natural science at the University of Gand devote one 

 hour weekly to the study of mineralogy, and it is for 

 these students that the book is primarily intended. From 

 this point of view we think that, as in most text-books, 

 more species are mentioned than is necessary ; such 

 rare minerals, for example, as chalcomenite and nitro- 

 barite should scarcely come within the range of the 

 elementary student, but the brief descriptions of the 

 commoner minerals leave nothing to be desired. 



There are several useful features in the book which 

 deserve special mention. In the case of most of the 

 minerals of commercial importance, such as mica, 

 apatite, cassiterite, galena and sulphur, a statement is 

 given of the annual world's yield and its approximate 

 value. 



Another important feature is a summary of the 

 minerals of Belgium with their localities, with which the 

 volume concludes. Such local information is extremely 

 useful, and this is the first authentic list of Belgian 

 minerals and localities which has been given. The list has 

 evidently been compiled with care ; special attention is 



