NATURE 



[March i, 19 17 



tastes, who have no aptitude for linguistics, into 

 studies that will be barren for them." 



Such phrases as these constitute a plea for 

 devotion of more time to literature, to history, 

 and especially to science. If the author's ideal 

 is tp be realised, it can only be done by an altera- 

 tion of the curriculum, to some extent at the 

 expense of classical studies. If " the first stage 

 of classical education should be left alone," how 

 does he propose to secure the wider type of educa- 

 tion which both he and ourselves advocate? 



It is on record that the head of an Oxford 

 coUeg-e urged that, since it was desirable that 

 clergymen should know Greek, and since it was 

 very often late in life before a man ultimately 

 made up his mind whether he was going to be a 

 clergyman or not, therefore all boys and young 

 men were to be regarded as potential clergymen 

 until that critical age was passed. We strongly 

 suspect the author of similar views, with the 

 exception that he would keep only the able boys 

 at classics and hand over the dullards to science. 



The second misconception is that science means 

 merely the acquisition of facts. Science can give 

 far more than the classicists imagine. The divi- 

 sion of branches of knowledge into "humanistic " 

 and "scientific" is an error of nomenclature; for 

 science may be made the most humane of all 

 studies. In the words of a recent manifesto : 

 " Imaginative f>ower indicates new fields in which 

 further knowledge of truth may be revealed ; its 

 full establishment depends upon accurate observa- 

 tion, with constant recourse to Nature for con- 

 firmation. The one aim of natural science is, in 

 fact, the search for truth based on evidence rather 

 than on authority. The special value of natural 

 science in the training of mind and character lies 

 in the fact that the history of the subject is a plain 

 record of the search for truth for its own sake." 



SCIENTIFIC ENGINEERING. 



(i) Legons sur le Fonctionnement des Groupes 

 Electrogknes en Regime Trouble. By Prof. L. 

 Barbillion. Pp. ii + 306. (Paris: Gauthier- 

 Villars et Cie, 1915.) Price 11 francs. 



(2) Electric Sivitch and Controlling Gear. By Dr. 

 C. C. Garrard. Pp. xviii + 656. (London: The 

 Electrician Printing and Publishing Co., Ltd., 

 n.d.) Price 155. net. 



(i) nr HE smooth working of steam or hydraulic 

 J- prime-movers directly coupled to dynamos 

 is one of great importance to supplv station 

 engineers. In this work Prof. Barbillion, the 

 director of the Technical Institute at Grenoble, 

 gives us a thorough and well-reasoned discussion 

 of the subject. Much of the discussion, we are 

 afraid, is too mathematical to be properly under- 

 stood by the ordinary English engineer^ but to 

 the specialist and the advanced student it will be 

 interesting and instructive. 



In the first chapter curves are given showing 

 how the torques produced by steam-engines and 

 hydraulic turbines vary with the velocity for a 

 NO. 2470, VOL. 99] 



given admission of steam or water respectively- 

 lixpressions are then found for the "useful " torque 

 produced by the prime-mover, and differential 

 equations are obtained for the dynamical equili- 

 brium of the combined set under various condi- 

 tions of load. These equations admit of easy solu- 

 tion. The problems of regulation and the role of 

 regulators are next discussed. The effects pro- 

 duced by flywheels, various types of Watt's 

 governor, air and oil brakes, etc., are investigated 

 mathematically and the solutions illustrated by 

 curves. 



Expressions are found for the magnitude of the 

 variation of the velocity produced by a given dis- 

 turbance, the case when the resisting torque varies 

 as the angular velocity being specially considered. 

 Various devices for damping out irregularities ia 

 speed are described, and finally in the last two 

 chapters a valuable descriptive study is made of 

 the mechanisms required to keep the engine 

 running at constant speed, and also of the devices 

 required to make the speed of the engine increase 

 with the load. The book is founded on a course 

 of lectures given by the author to technical 

 students. It illustrates well the great practical 

 value of mathematics to engineers. 



(2) As a work of reference this book is of value. 

 Much of the information in it is novel, and the 

 problems discussed are those which are exercising 

 the minds of electrical engineers at the present 

 time. Many of the practical devices in everyday 

 use have their limitations, and some are of very 

 doubtful utility. Dr. Garrard's critical remarks, 

 therefore, will be most helpful in clearing up the 

 mystery attending their operation. 



In the first chapter materials and manufacturing 

 methods are described. It shows clearly how 

 scientific ordinary commercial engineering is 

 becoming. In the old Jays the purchaser of raw 

 materials made a cursory inspection of all the 

 samples, and if they appeared to be of the same 

 quality he accepted the lowest price. This is no 

 longer the case. Consider, for instance, the pur- 

 chase of the oil used for insulating high-tension 

 apparatus. The buyer insists on knowing the 

 electric strength, the flash-point, the viscosity, the 

 specific gravity, the freedom from acid and alkali, 

 the mineral impurities and additions, and the rate 

 at which oxidation products are formed when 

 ozonised air is passed through the oil. Similarly, 

 other materials used in construction will have ta 

 conform — or will soon have to conform — to rigid 

 and highly scientific specifications. In this con- 

 nection the work done by the Engineering 

 Standards Committee and by the many committees 

 of the Institution of Electrical Engineers is worthy 

 of high commendation. The co-operation betweerr 

 engineers, business men, mathematicians, phy- 

 sicists, and chemists is in every way satisfactory, 

 and promises well for the future industrial welfare 

 of the countr}'. 



Descriptions are given of apparatus for making 

 and .breaking electrical circuits, for obviating 

 danger, for regulating the current and pressure,, 

 for starting and controlling running machinery. 



