REVIEWS. 
Association, to the rules of which affiliated clubs must conform. Whilst it is 
true that in the early days model aeroplaning played a very important part in 
the development of aeronautics, in view of the great advances made in the know- 
ledge of scientific principles, it is very doubtful whether the author’s claims 
for its future importance can be justified. Of course, the study of the properties 
of aerofoils by the use of models in wind tunnels, such as is being carried out by 
the National Physical Laboratory and the Eiffel Laboratory, is of the greatest 
yalue, and has had very important results in evolving the most efficient wing 
sections for various specific duties; but that is a subject which is not dealt with 
in the present volume. ‘Uhe book contains little information that is of scientific 
yalue, such as is furnished in recent works on aeroplane design and construction, 
and the author does not, apparently, appreciate the fact that the study oi 
aeronautics can only be successfully attempted by those possessing a good know: 
ledge of mathematics and physics. To persons desiring to construct model 
aeroplanes for use as a pastime, the book will be of considerable interest and 
value. » 
Slide Rules, and How to Use Them, by T. Jackson, M.1.M.E. London: Chap- 
man & Hall, 1920. Pp. 31. Prime, 1s. 6d. net.—One of the most striking 
developments in modern technical methods of calculation has been the enormous 
increase in the use of slide rules. In the present booklet, the principle of the 
rule and the main features of different makes are explained. The first eighteen 
pages deal with the ordinary pattern of “Grave” (or “ Mannheim”) slide rule 
and show how the different operations—multiplication, division, proportion, 
reduction squares and cubes, square roots and cube roots, logarithms, &c.—are 
carried out. The special markings found on one or other of the various makes 
are also explained. In the following pages, information is given regarding 
“log-log” rules, and some special rules, such as the “ Fix,” the “ Rietz,” the 
* Long-short,” the “C.E.M.,” the “Prof. Nestle,’ and the “Omnes ” rules. In 
an appendix, particulars are given of the “ watch form” calculator. The booklet 
will be of considerable value to engineering students in explaining the principles | 
and methods of using slide rules. Its value would have been enhanced by the 
inclusion of an explanation of the “spiral” rule. 
PUBLICATIONS RECEIVED. 
Insects of Heonomie Importance, by G. W. Herrick. Macmillan & Co., New 
York. 1920. © ; 
Australian Quarantine Service: Commonwealth Serum Laboratories and their 
Work. 1920. 
Turbine Steels: A research into their mechanical properties, by Dr. Hatfield. of 
_ the Brown-Firth Research Laboratories, and H. M. Dunean, B.Se. : 
New Zealand Institute: Transactions and Proceedings for 1919, vol. 52. 
Western Australian Forests Department: Report for 1918-1919. 
Vietorian Institute of Refrigeration: Proceedings of First (Annual) Conference. 
1920. 
United States Department of Agriculture, Bulletin No. 772.—The genera of 
grasses of the United States, with special reference to the economic series, 
by A. S. Hitcheock, pp. 307. 1920. 
British Engineering Standards Association: Standard Specifications :— 
No. 1 (revised July, 1920). Lists of British Standard Rolled Steel Sections 
for Structural Purposes. . 
No. 12 (revised 1920). British Standard Specification for Portland Cement. 
No. 94. British Standard Specification for Watertight Glands for Electric, 
Cables. 1920. 
No..97. British Standard Specification for Watertight Fittings for Incandes- 
cent Electric Lamps. 1920. ; 
No. 100. British Standard Dimensions for Body Spaces and Frame Ends for 
Chassis for Private Automobiles. 1920. 
123 
