lOO 



NATURE 



[March 24, 192 1 



notion; but the claim would have been a barren 

 one. 



One thing we miss in Maxwell's discussion — 

 that is, the curious theorem of the splitting of 

 the velocity of the particle describing the orbit 

 into two constant components, one at right angles 

 to the radius vector, and the other perpendicular 

 to the major axis of the orbit. It is curious that 

 there should be this relation. 



A propos of the principle of least action, dis- 

 cussed in appendix ii., it is remarkable that if 

 the major axis of an elliptic orbit, for a particle 

 moving, as in the case of Nature, under a force 

 along the radius vector from a focus, and vary- 

 ing as the square of the distance, is given, the 

 action (the space-integral of the momentum round 

 the orbit) is independent of the eccentricity of the 

 orbit. It depends only on the major axis, so that 

 it is the same for a circular orbit as for a long, 

 narrow one. This gives a means of solving 

 various problems. 



Connected with this is another theorem that 

 the kinetic energy of the particle at distance r 

 from the same centre of force, in a hyperbolic 

 orbit of semi-transverse axis a (equal to the semi- 

 major axis of the elliptic orbit), exceeds, and in 

 the elliptic orbit falls short of, the expansion 

 mii/r of potential energy, from infinity to the 

 distance r, by the time or average of the kinetic 

 energy of the elliptic motion. 



One thing we cannot understand in the popular 

 treatment of hodographic theory : Why is it 

 always regarded as an affair of particle dynamics 

 only? If we set up, or imagine set up, a sequence 

 of vectors representing the angular momentum of 

 a rigid body, say that of an aeroplane, the velo- 

 city of the extremity of the vector is in magni- 

 tude and direction the rate of change of the 

 angular momentum. This might help to prevent 

 that pernicious " ignoration " of the direction of 

 the angular momentum vector, and its variation, 

 which characterises so many uninstructed but 

 apparently influential people. A. Gray. 



A Socialist Commonwealth. 



A Constitution for the Socialist Commonwealth of 

 Great Britain. By Sidney and Beatrice Webb. 

 Pp. xviii-F364. (London: Longmans, Green, 

 and Co., 1920.) 125. 6d. net. 



IN this volume Mr. and Mrs. Webb set them- 

 selves to build " an efficiently working, 

 genuinely democratic constitution " out of the 

 materials that are already to hand. The distinc- 

 tive feature of the Socialist Commonwealth of 

 Great Britain will be the division of the labours of 

 our present overworked Parliament between two 

 NO. 2682, VOL. 107] 



co-equal bodies, the Social and the Political Par- 

 liaments, both elected on a geographical basis by 

 all the adult citizens. The Political Parliament 

 will deal mainly with defence, justice, and foreign 

 affairs, and will have a keen eye to the protection 

 of the liberty of the individual. To the Social 

 Parliament all else falls — labour, health, educa- 

 tion, the control of industry, and care for the 

 interests of generations yet unborn. In the hands 

 of the Social Parliament rests also the power of 

 the purse ; from which it may be anticipated that 

 the Political Parliament, for all its nominal 

 equality, will have to mind its " p's and q's. " 



Perhaps the most fruitful part of a very sugges- 

 tive work is contained in the proposals for the 

 reconstruction of local government. On this the 

 authors speak with ripe experience of actual ad- 

 ministration, as well as with their usual wide 

 theoretical knowledge. The unit of local govern- 

 ment is to be the ward, though different wards 

 are to be grouped and re-grouped in such a way 

 as to give a unit of appropriate size for the con- 

 duct of each municipalised service. Economic 

 efficiency will thus no longer be subservient to the 

 historical accident of municipal boundaries. 



Industry will of course be "socialised." 

 Socialisation will take a variety of forms, the 

 common features of which will be production for 

 use and not for profit, and the separation 

 of control from actual administration. National- 

 isation, municipalisation (of which a great 

 expansion is anticipated), and organisation on 

 the co-operative principle exhibited by the 

 existing Consumers' Co-operative Movement 

 will be the three great types. The national- 

 ised industries will be administered by a 

 hierarchy of national boards, regional councils, 

 and works or pit committees, responsible to a. 

 Standing Committee of the Social Parliament, and 

 goaded into efficiency by the supervision and con- 

 trol of an independent department. Bureaucracy 

 is anathema. A limited share in administration 

 will be accorded to the appropriate organisations 

 of workers, although Mr. and Mrs. Webb believe 

 in the conduct of. industry by the community for 

 the community, rather than by the workers for 

 the workers. The charwomen who clean the 

 schools are not to dictate ,i«rf»at shall be taught^ 

 there. Vocational organisations, of the form of 

 our present trade unions and professional asso- 

 ciations, will be concerned rather with the protec- 

 tion of the status of the several vocations, the 

 promotion of all kinds of scientific research (on 

 which the authors lay great stress), and the main- 

 tenance of professional honour. For a national 

 body elected on a vocational basis, such as a 

 regenerated Trade Union Congress, the authors 



