340 



NA TURE 



[August i i, 1904 



amount of theory as a basis, and a book which does 

 not supply, in each branch, the necessary minimum 

 hardly deserves to claim the title of a " comprehensive 

 treatise." Maurice Solomon. 



PIONEER IRRIGATION. 

 Pioneer Irrigation for Farmers in the Colonies. By 

 E. O. Mawson, M.Inst.C.E. With Chapters on 

 Light Railways, by E. R. Calthrop, M.Inst.C.E. 

 Pp. xvi + 260. (London : Crosby Lockwood and 

 Son, 1904.) 



THE preface states that " this book has been written 

 with the object of supplying pioneer farmers, in 

 arid countries, with information which may assist 

 them in conserving the precarious rainfall, and 

 utilising it for the irrigation of crops " ; also that 

 " only the most homely contrivances, such as can be 

 constructed and worked without professional advice 

 or skilled labour are suggested "; and that the object 

 " throughout the volume has been to demonstrate, in 

 the simplest possible manner, how the available water- 

 supply — whether surface-flow or underground — can be 

 used for irrigating crops by means of works easily 

 constructed at a small expenditure, without fear of 

 danger in case of failure." The book, however, is 

 not in reality confined within these prescribed limits ; 

 for it refers to earthen dams, with puddle trench, waste 

 weir, and outlet valve tower, masonry dams of moderate 

 height for forming reservoirs in gorges, a masonry 

 aqueduct of several spans, and a barrage or weir across 

 an apparently wide river, closed along the upper portion 

 by a series of automatic sluice-gates. The works, 

 indeed, shown in some of the woodcuts, and especially 

 on plates 3 to 8, 10, and 19, could not possibly be 

 regarded as homely contrivances, capable of being 

 easily carried out by pioneer farmers, without skilled 

 labour, at a small cost, and without danger to the 

 neighbourhood in the event of failure. 



The chapters on the value of irrigation and sources 

 of water-supply, underground waters, methods of 

 irrigation, and the cultivation of irrigated crops, 

 vegetables, and fruit trees, contain much information 

 which would be very useful to persons engaged in the 

 cultivation of arid districts ; but most of the works 

 described in the chapters on dams and weirs, canals, 

 sewage irrigation, and automatic sluice-gates, would 

 be wholly beyond the resources of pioneer farmers. 

 The storage of rainfall, the collection of the run-off of 

 water in the rainy season by open tanks formed in 

 depressions enclosed by low banks, and the drawing of 

 underground waters from wells, are works which can 

 be readily undertaken with great benefit by cultivators 

 of arid lands ; but the formation of large reservoirs 

 by damming up valleys, and the raising of the water 

 level of rivers and the conveyance of the water con- 

 siderable distances in irrigation canals, constitute 

 works which have to be carried out by a company, the 

 local authorities, or the Government, for the irrigation 

 of large tracts of land. Sewage irrigation, moreover, 

 can only be made use of in the neighbourhood of large 

 communities, and is not available amongst the sparse 

 population of a newly-settled agricultural district. 

 NO. 18 I 5, VOL. 70] 



In a chapter on automatic sluice-gates, a system of 

 hinged gates or shutters is advocated for raising the 

 water level of reservoirs and rivers, which has 

 apparently been patented by one of the authors ; but it 

 is not stated that the design has been put into oper- 

 ation ; and such automatic contrivances, as in the case 

 of the movable shutter weirs employed long ago for 

 the canalisation of some rivers in France, are liable to 

 be very irregular in their action. The two concluding 

 chapters furnish some interesting particulars about 

 light railways, which are introduced with the view that 

 the conveyance of the produce of irrigated lands to a 

 market is second only in importance to the supply of 

 water. Such works, however, with the great 

 advantages that they afford, have to be carried out in 

 the midst of a thriving- community, where both capital 

 and revenue are available ; and they are beyond the 

 scope of pioneer farmers who are extending cultivation 

 into new, unoccupied districts. A long appendix is 

 given at the end of the volume, containing various 

 memoranda, tables, and particulars about materials 

 and tools, which may be of service in irrigation works 

 .•md farming. The book is, in fact, a short manual 

 on irrigation works in general, with some account of 

 the construction, suitable gauges, and rolling-stock of 

 light railways. 



OUR BOOK SHELF. 



Lehrbucli der Stereochemie. By A. Werner. Pp. 

 xvi+474. (Jena: Gustav Fischer, 1904.) Price 

 10 marks. 



This book had its origin in the courses of lectures 

 on stereochemistry delivered during recent years by 

 Prof. Werner in the University of Zurich. The 

 systematic form of the lectures has been adhered to, 

 but by the addition of numerous tables and many 

 hundreds of references to original sources, the author 

 has produced a comprehensive handbook which must 

 prove of great utility, not only to the general chemist 

 who wishes to know something of the advances 

 made in stereochemistry since the conception was 

 first put forward, but also to the specialist whose 

 work is directly concerned with the subject. Notwith- 

 standing the wealth of detail, the book is of moderate 

 compass, and whilst compression in the theoretical 

 portions is occasionally carried to such an extent as 

 to interfere somewhat with intelligibility, yet the book 

 is on the whole both readable and easily compre- 

 hensible. The eminence of the author as an investi- 

 gator in some of the most obscure fields of stereo- 

 chemical research is sufficient guarantee of his mas- 

 tery of both theory and material. 



The work is composed of two chief parts, of 

 which the first deals with stereoisomerism, divided 

 into subsections according to the elements involved. 

 The first subsection is naturally devoted to the 

 stereoisomeric carbon compounds, and occupies about 

 half of the whole book. In it are treated, amongst 

 other matters, the theory of the asymmetric carbon 

 atom, mirror-image isomerism, racemism and the 

 resolution of racemic compounds, determination of 

 configuration in open chains (more particularh 

 in the sugars and related substances) and in closed 

 chains, the quantitative relations between rotation 

 and the nature of the asymmetric carbon atom, 

 cis-trans isomerism in cyclic compounds, and the 

 geometric isomerism of ethylenic compounds. The 



