NATURE 



139 



THURSDAY. OCTOBER 



^9^5- 



PRACTICAL ENGINEERING. 



(i) Plain and Reinforced Concrete Arches. By 

 Prof. J. Melan, Authorised Translation by 

 Prof. D. B. Steinman. Pp. x+i6i. (New 

 York : J. Wiley and Sons, Inc. ; London : 

 Chapman and Hall, Ltd., 1915.) 8^. 6d. nh.. 



(2) Masonry: A Short Text-book on Masonry 

 Construction, including Descriptions of the 

 Materials used, their Preparation and Arrange- 

 ment in Structures. By Prof. M. A. Howe. 

 Pp. ix + 160. (New York : J. Wiley and Sons, 

 Inc.; London: Chapman and Hall, Ltd., 1915.) 

 Price 65. 6d. net. 



(3) Railroad Field Manual for Civil Engineers. 

 By Prof. W. G. Raymond. Pp. vii + 386. 

 (New York : J. Wiley and Sons, Inc. ; London : 

 Chapman and Hall, Ltd, 191 5.) 125. 6d. net. 



(4) Working Data for Irrigation Engineers. By 

 E. A. Moritz. Pp. xiii + 395. (New York : J. 

 Wiley and Sons, Inc. ; London : Chapman and 

 Hall, Ltd., 1915.) 175. net. 



(i) " T)LAIN and Reinforced Concrete Arches" 

 X is an American translation by Dr. 

 Steinman of a German treatise by Prof. J. Melan, 

 who is an authority on structural design, and has 

 invented a well-known system of reinforced arch 

 construction. The treatise is thorough, accurate, 

 and clear. After considering the theory of hinged 

 and hingeless arches, the latter by both analytic 

 and graphic methods, the effects of temperature, 

 displacement of the abutments, and non-vertical 

 loads are examined. Then come arches with elastic 

 abutments, the results being applied to a treat- 

 ment of arches continuous over several spans, on 

 lofty piers. Reinforced arches are next considered, 

 and there is a valuable chapter on the recalcula- 

 tion of the stresses in an arch ring by a more 

 rigorous method after it has been provisionally 

 designed. The calculations of arches, especially 

 of reinforced arches, are laborious, and fuUy- 

 worked-out examples of two actual bridges are 

 g"iven, the solutions being in one case by analytic, 

 in the other by graphic, methods. There is a very 

 useful chart for designing concrete sections with 

 double reinforcement. 



Prof. Melan has written several books on arched 

 construction, and this one appears to be a con- 

 densed but fairly complete statement of the present 

 state of arch theory. In investigating the critical 

 conditions of loading for each arch section, the 

 method of influence lines is used with great ad- 

 vantage. For abbreviating labour in provisional 

 NO. 2397, VOL. 96] 



designing, easily applied simple approximate ex- 

 pressions are found. In many cases of double 

 reinforcement the steel bars in compression are 

 understrained. To obviate this. Prof. Melan has 

 invented the method of putting them into an 

 initial condition of thrust by loading them with 

 part of the weight of the centring. The economy 

 obtained is of value, and the method has been 

 adopted abroad, though it is probably little known 

 here. The treatise is very practical, if that can 

 be said of a theoretical treatment of the subject, 

 and can be strongly recommended to any en- 

 gineer concerned in designing concrete arched 

 bridges. 



(2) "Masonry," by Prof. Howe, is an ele- 

 mentary, mainly descriptive account of stone 

 masonry, brickwork, and concrete construction, 

 not including reinforced concrete. Quarrying and 

 manufacturing operations are briefly described, 

 and the different kinds of brick and stone 

 masonry, mass and block concrete, and tools used 

 in different operations. The cement gun is de- 

 scribed, used for giving a dense surface finish to 

 mass concrete by blowing a cement grout against 

 the surface. 



(3) "The Railroad Field Manual," by Prof. Ray- 

 mond, consists almost entirely of tables required 

 in surveying and laying out curves. Its peculiarity 

 is that the centesimal in place of the sexagesimal 

 division of angles is adopted. The author remarks 

 that, in practically every railway curve problem, 

 it is necessary at some stage of the solution to 

 transpose from minutes and seconds to decimals 

 of a degree or vice versA, and that it would re- 

 quire much less mental labour to lay out sub- 

 chords if the transit were divided decimally, and, 

 of course, if suitable trigonometrical tables were 

 available. The tables seem to have been carefully 

 arranged and to be accurate. Of course, if the 

 author's method is to be used, the verniers on any 

 transit made as at present would have to be altered 

 to read hundredths of a degree, but this is not a 

 very serious matter. Only experience can prove 

 whether the economy of labour is sufficient to 

 make the change desirable. 



(4) "Working Data for Irrigation Engineers" 

 consists in the main (a) of hydraulic diagrams and 

 tables giving discharge of canals, pipes, orifices, 

 and weirs ; (h) of structural diagrams and tables 

 giving earthwork quantities, bending moments on 

 beams, tables for reinforced concrete and timber, 

 etc. Large use is made of graphic diagrams. 

 Some of the information is derived from the re- 

 cords of the U.S. Reclamation Service. The 

 author is competent, and the book will be of. 

 service to irrigation engineers. ' 



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