REVIEWS 509 



ments of French scientists will not be used to feed the flames of Jingoism. 

 Doctor Matisse, it is only fair to say, gives no occasion for complaint in this 

 respect. One can only praise his lucid exposition and his wise choice of apt 

 quotations. A. Wolf. 



Hyperacoustics. Division II, Successive Tonality. By John L. Dunk. 

 [Pp. xi + 160.] (London : J. M. Dent & Sons, Ltd., 1921. Price 5s. 

 net.) 



This second volume of Hyperacoustics deals with its subject in the same 

 strikingly original manner that the author evinced in his somewhat mystical 

 treatment of simultaneous tonality given in the earlier volume. To form 

 a bridge between the two divisions of the subject this second volume includes 

 a 60-page summary of the contents of the first. 



E. H. B. 



The Electric Furnace. By J. N. Pring, M.B.E., D.Sc. Research De- 

 partment, Royal Arsenal, Woolwich. (Monographs on Industrial 

 Chemistry, edited by Sir Edward Thorpe, C.B., F.R.S.) [Pp. 

 xii + 485, with numerous plates and illustrations.] (London : Long- 

 mans, Green & Co. Price 325. net.) 



Practically speaking, we may divide electro-thermal operations into two 

 classes, those where a vigorous and fundamental reaction occurs, such as the 

 formation of carborundum, calcium carbide, aluminium, etc., and those where 

 the purely chemical changes are slight, such as the production of graphite, the 

 smelting of iron and steel and other metals and alloys. 



Hitherto it has been felt, rather than reasoned, that in countries such as 

 Great Britain, where water-power is very scarce, we could only hope to utilise 

 electricity for the first class of operations, whilst the use of electric 

 furnaces for the heating of great masses of metal was thought to be economi- 

 cally impossible. 



Dr. Pring is at great pains to show the fallacy of the argument, as in direct 

 fuel heating the efficiency is probably well below 20 per cent, owing to flue 

 losses, etc., whilst with internal electric heating an efficiency of 80 per cent, 

 or more may be attained, which leaves a wide margin in favour of the electric 

 furnace. 



It is to be expected, therefore, that the electric furnace will come rapidly 

 into wide use in all countries where reasonably cheap fuel is available, owing 

 to its economy, cleanliness, and easy control, and for all those whose interests 

 lie in these directions the present book should be invaluable. 



It is impossible here to do more than indicate the scope of the book, which 

 deals with the principles of furnace design, their cost and efiiciency, the pro- 

 duction of calcium carbide, cyanamide, synthetic ammonia and nitric acid, 

 iron, steel, copper and tin smelting, carborundum, graphite, phosphorus, and 

 so on. 



^The illustrations and diagrams are extremely clear and up to date, and 

 the author's long experience as a teacher at Owen's College ensures a clearness 

 of expression which is very welcome. Although one or tv\-o books on the same 

 subject have been published since the last English edition of Moissan's classic 

 work in 1904, it is doubtful whether any of them attain to quite the same 

 high standard of clarity and conciseness as Dr. Pring's comprehensive work, 

 and he has rendered no small service both to chemists and electricians iu 

 undertaking the production of the very excellent volume now publisiied. 



F. A. M. 



