REVIEWS 339 



structural parts and controls. Under Part III. the strength of construction is 

 considered ; Part IV. has 30 pages devoted to the airscrew — an extraordinary 

 example of concise thoroughness. Part V. has four chapters — (1) Steady Motion 

 in Flight, (2) Stability— Mathematical Theory, (3) Stability — Experimental, (4) The 

 Complete Machine. A useful glossary of aeronautical terms and the folding 

 plates complete the volume. 



The authors anticipate that the science ot aeronautics " will shortly take its 

 proper position in the curriculum of every university and technical college." 



The foundation of the Zaharoff Professorship of Aviation gives practical 

 colouring to this anticipation, and this volume, in addition to being of general 

 value to the man of science, should be of the greatest value to the student of 

 aviation. 



J. Wemyss Anderson. 



Tidal Lands : A Study of Shore Problems. By Alfred E. Carey, M.InstX.E., 

 and F. W. Oliver, F.R.S. [Pp. xiv + 284, with 56 figures and 29 plates.] 

 (London ■ Blackie & Son, Ltd., 1918. Price 12s. 6d net.) 



Few, probably, of the vast numbers who spend their leisure by the sea pause to 

 dwell upon the romance that is embodied in the narrow intertidal zone we term 

 the foreshore. For the coastal landowner, however, as for " those who go down to 

 the sea in ships," the word connotes the battle-ground of elemental forces, a scene 

 of never-ceasing change. The volume under review deals with the fascinating 

 problems associated with this region, and is essentially a practical contribution to 

 the subject of coastal maintenance and reclamation. 



Hitherto the control of erosion and accretion has been regarded as peculiarly 

 the province of the engineer and, in consequence, protection devices have become 

 almost synonymous with wooden piles or stone and concrete groynes. There is 

 an appeal of the massive to the human mind which has found its expression in the 

 primitive forms of construction both in engineering and in architecture. It is only 

 with the acquisition of knowledge that the ponderous gives place to the flexible, 

 which, because it yields, the oftener remains unbroken. Undoubtedly the most 

 notable feature of the present volume is the development of this evolutionary 

 tendency, in the emphasis laid upon the role of plants in protection and their 

 paramount utility in the artificial prevention or direction of the natural forces of 

 erosion and accretion. Full recognition is given to the value of. engineering 

 constructions which constitute a useful and necessary adjunct to the utilisation of 

 plants, but it is on these latter, with their remarkable capacity for meeting the 

 many vicissitudes of the environment, that reliance is chiefly placed to curb and 

 govern the forces of wind and water. In the words of the authors, "one of the 

 intentions of the present book is to consider if, and to what extent, the con- 

 structions of the engineer may be supplemented, modified, or even replaced, by 

 the employment of vegetation suitable to the purposes in view." The collaboration 

 of engineer and botanist has ensured the maintenance of a true perspective 

 between the two standpoints, and, though the greater part of the subject-matter 

 is devoted to the living implements, constructional works are adequately treated 

 in relation to the varied problems. 



The value of vegetation for the fixation and maintenance of dunes has long 

 been recognised, though much neglected in this country. The principle is here, 

 however, extended to the control of shingle beaches, salt marshes, in fact, to all 

 types of tidal lands. The work is one which should be carefully studied by all 

 who are concerned with the conservation of our coastal areas, but even for those 



