/\PRIL 26, 19 1 7] 



NATURE 



i6. 



a whirl of air which moves in the same direction as 

 the sound will increase the pitch of the note heard, 

 and vic3 versa. If an instrument could be devised for 

 recording- rapid biTt slight changes of pitch of musical 

 notes, a fairly accurate estimate of the irregularities 

 of atmospheric velocities could be obtained. 



C. E. Stromeyer. 

 Lancefield, West Didsburj-, 

 April 15. 



Gravitation and Thermodynamics. 



As pointed out by Sir Oliver Lodge in Nature of 

 April 5, the case I cited of a disc pivoted about its 

 centre of mass and started in motion does not lead 

 to perpetual motion in the ordinar}- sense. But, as 

 it seems to me, there will be long-sustained, oscillatory, 

 motion. On rotating the disc by a small angle, the 

 descending half will gain, and the ascending half 

 will lose, heat. A turning-moment will arise, and 

 will increase until the angle turned is s-/2. It will 

 then decrease until, when the angle turned is n-, the 

 moment is nil. This position gives the condition, 

 quoted by Sir Oliver Lodge, of thermal symmetry 

 about the vertical diameter of the disc. As the disc 

 continues to rotate, due to its momentum, a moment 

 in a reverse sense will be set up, so that when the 

 whole rotation is nearly 2t, the rotation will be re- 

 versed. We shall thus obtain an oscillatory- motion, 

 long sustained if small friction is involved. In the 

 final position the disc will have rotated from its 

 initial position by angle «•. Such a result would be 

 phenomenal, since the mere act of rotating the disc 

 by an infinitesimal angle would, in efTect, convert a 

 condition of neutral, into one of unstable, equilibrium. 



Dr. Todd has suggested that this peculiar efTect 

 would not arise if d3jdr is positive. We should then 

 have the remaining peculiar efTect, viz. a condition 

 of neutral equilibrium would by a rotation be con- 

 verted into one of stable equilibrium. Will this pro- 

 posal satisfy philosophers? ' P. E. Shaw. 



Floating Earths. 



I SENT Dr. Leaf's letter on "Floating Earths" 

 (Nature, March 15) to M. Salomon Reinach, and 

 append his answer, which, I think, partly explains 

 the matter. J. Offord. 



94 Gloucester Road, South Kensington, S.W.7. 



Dear Mr. Offord, — 



You won't build on uncertain texts. Dr. Leaf 

 translates " in the case, of an islet in Tyrrhenia," 

 reading vija-is, which is corrupt ; I prefer yi; rts (Corey), 

 a certain variety of earth in Tyrrhenia — the remainder 

 concerning natural science, excepting ^ ra dpyvpcafiara 

 (Kfju'trrtTai, words which I take in the "trivial 

 meaning." — Yours truly, S. Reinach. 



Musee National, Saint-Germain, 

 Le 4 avril 1917. 



The New Food Orders. 



I\ my article in Nature of April 12 there were in- 

 advertently omitted, probably by myself, some words 

 which make one of my suggestions an absurdity. In 

 reference to the meat ration of the Army, what I 

 meant to say was that " a part of the large meat 

 allowance might, with advantage, be replaced by its 

 equivalent in energy-value of carbohydrate." 



W. M. B.4YLISS. 



EMPIRE DEVELOPMENT AND ORGANISA- 

 TION. ^ 

 T^HE final report of the Royal Commission on 

 -'■ the natural resources, trade, and legislation 

 of certain portions of his Majesty's Dominions has 

 recently been issued and presented to both Houses 

 of Parliament. The commission came into being 

 in consequence of a resolution passed by the Im- 

 perial Conference in 191 1. The members were 

 app>ointed in April, 1912, six representing- the 

 United Kingdom, and one each the self-governing 

 Dominions of Canada, Australia, New Zealand, 

 the Union of South Africa, and Newfoundland. 

 India, the Crown Colonies, and the Protectorates 

 were not included. 



ITie sittings of the commission ended, as they 

 began, in London. In the interval the commis- 

 sioners made four tours : the first to New Zealand 

 and .\ustralia, the second to the L'nion of South 

 .-\frica, the third to Newfoundland and eastern 

 Canada, and the fourth to central and western 

 Canada. They visited every capital of every 

 State or Province in each of the Dominions, and 

 took evidence in all the most important cities. 

 They say : — 



In the course of this period we have travelled for 

 many tens of thousands of miles to, through, and 

 from the self-gov-^rning Dominions of your Majesty's 

 Empire. In every district of this vast area we have 

 done our utmost, collectively and individually, to make 

 ourselves acquainted with its characteristics, its his- 

 tory, and its aspirations, as we hope, and indeed 

 believe, not without success. We have also had the 

 opportunity of hearing personally the opinions of 

 every section of its population upon the problems upon 

 which we have been engaged. It is therefore with 

 a certain confidence as to their value that we present 

 our unanimous conclusions for your Majesty's con- 

 sideration. 



It is to be noted, however, that in May, 191 5, 

 the Government of the Commonwealth of Aus- 

 tralia withdrew its representative from the com- 

 mission, and the final report does not contain the 

 signature of any representative of that Dominion. 

 No reason is given for this action on the part of 

 Australia. 



The main object of the commission was to in- 

 quire into, and report upon, (a) the natural re- 

 sources of the five self-governing Dominions and 

 the best means of developing them ; (b) their trade 

 with the L^nited Kingdom, each other, and the 

 rest of the world ; and (c) their requirements and 

 those of the United Kingdom in reg^ard to food 

 aniJ raw materials, together with the available 

 sources of supply. Broad as the scope of this 

 inquiry was, it could not be kept within the pre- 

 scribed limits. The commissioners say : — 



During the whole course of our investigations . . . 

 we have been conscious of two strong and impelling 

 impressions. 



First, for Empire purposes no survey can be com- 

 plete without including India, the Crown Colcwiies, 

 and the Protectorates. In themselves, and even as 

 now develoi>ed, they form too vital and important a 

 part of the Empire -to be left out of present calcula- 

 tions. But it is plainly evident that their poten- 

 tialities, measured by any fair standard, are immense. 



NO. 2478, VOL. 99] 



