January 21, 19 15] 



nature; 



:)D/ 



of German domination. Apart altogether from the 

 commercial aspect, there is, therefore, a gfreat 

 oblig-ation of patriotism involved. The scheme 

 put forward — possibly as a ballon d'essai as 

 regards details — certainly requires modification, 

 but from it can be elaborated a national and co- 

 operative effort which is bound to succeed. 



Even to discuss the question of the breakdown 

 of the proposal to make ourselves Independent 

 of German products, is almost a triumph for the 

 enemies of our country, and a national humilia- 

 tion for us. Let us all take as a starting-point of 

 our deliberations that the thing- must be done, and 

 then the details of how to do it will fall into 

 proper perspective. 



Finally it may be pointed out that incidental 

 advantages of enormous national value will accrue 

 as the result of the successful fruition of this 

 dye-ware manufacture scheme. The necessity for 

 dealing with our industries from a national, rather 

 than an individualistic, point of view will be more 

 fully recognised by the Government and by the 

 public. The necessity for the use of scientific 

 method and control of our industries will be 

 strongly emphasised. The claims of patriotism 

 and the value of co-operation in commercial 

 matters will receive fuller consideration, and 

 lastly, the establishment of a powerful company 

 for the manufacture of organic dyestuffs will afford 

 protection to our great industries concerned in the 

 manufacture of inorganic chemicals, an attack on 

 which was beginning to be organised. 



Xow is our opportunity, and everything is pro- 

 pitious. Patriotism and self-interest are alike 

 clamouring for the establishment of a large dye 

 manufacturing concern, and the Government offers 

 its support. One essential thing may, however, 

 be overlooked — the new company is foredoomed to 

 failure unless a scientific, rather than a purely 

 commercial spirit permeates the management, and 

 an apf>eal is made to the Government and to the 

 eminent business men forming the committee who 

 have issued the scheme that in its final form it 

 may include a full recognition of this fundamental 

 point. Walter M. Gardner. 



ELECTROMAGNETIC WAVES. 

 Electromagnetic Theory. By O. Heaviside. 

 Vol. iii. Pp. ix + 519. (London: The Elec- 

 trician Printing and Publishing Co., Ltd., n.d.) 

 Price 215. net. 



IT is scarcely necessary to recommend to those 

 interested in electromagnetic theory any book 

 or article written by Dr. Oliver Heaviside. Since 

 1S99 the scientific world has had in possession the 

 NO. 2360. VOL. 94.] 



first and second volumes of his '* Electromagnetic 

 Theory " ; and these volumes hold a unique place 

 in the literature of the subject. The fir^t volume 

 was reviewed in Nature of 1894 (see vol. li., 

 p. 171), and the second in 1899 (see vol. Ix. , 

 p. 589). Now, after fourteen years of waiting, 

 the world is enriched with the third and pre- 

 sumably the last volume containing the author's 

 views upon the later developments of this ever- 

 growing science. 



The third volume is marked by all the charac- 

 teristics of the earlier volumes. There is shown 

 the same powerful grasp of the great principles 

 of Maxwell's theory, the same intuitive intimacy 

 with the hidden features of the electromagnetic 

 field, the same boldness in materialising the 

 mathematical conceptions, the same fearlessness 

 in attacking really difficult problems, inventing 

 new mathematics if necessary, or ingeniously 

 turning to account old results got in different 

 lines of inquiry. Every now and again he runs 

 oflf into a side alley, at first sight quite away from 

 the natural highway, but out of which he leads us 

 back with some substantial gain, fitting us the 

 better for the strenuous work to come. And we 

 need all our best powers to follow his lead. There 

 is no shirking of difficulty ; there is no yielding 

 to authority. Every new fact or hypothesis in 

 electromagnet! sm must pass through his critical 

 mind, every new theory be looked at carefully 

 and the evidences for and against balanced against 

 each other. The book is indeed the product of a 

 hard-working and ingenious mind, and bears 

 throughout the unmistakable marks of the per- 

 sonality of the author. 



The modified quaternion analysis which Dr. 

 Heaviside introduced into the earlier volumes is 

 used with good effect when occasion demands. 

 There is, of course, nothing t.alismanic in the 

 particular notation which Dr. Heaviside has 

 adopted ; and it seems a pity to stir up old con- 

 troversy by reproducing letters written last 

 centurj'. When the author accuses Tait of view- 

 ing the same thing quite differently according as 

 it is clothed in his (Tait's) favourite quaternion 

 garb or in so-called vectorial vestments, he uses 

 a sword with a cutting edge in the hilt. We have 

 simply to change Tait to Heaviside and inter- 

 change the words quaternionic and vectorial, and 

 the truth remains. And the curious thing is that 

 all the change which Dr. Heaviside makes in the 

 Hamiltonian notation is to drop the S for scalar 

 and change the sign. Meanwhile more recent 

 vector analysts equally despise Hamilton and 

 Heaviside, and add to the confusion by inventing 

 their own precious notations. 



The subject-matter of the present volume is 

 very simply described. It has to do with the 



