October 25, 1906] 



NATURE 



647 



cussiuns that take place at the meetings of the Geological 

 Society of South Africa (Proceedings of the Society for 

 1905), and by the considerable space given to written 

 criticisms and replies. The Transactions would be very 

 incomplete without these additions, which may be com- 

 mended to the notice of many publishing societies in our 

 islands. Dr. F. W. Voit, for instance, read a paper 

 (Trans. Geol. Soc, S. Africa, vol. viii., p. lod) on 

 September 4, 1905, entitled " Preliminary Notes on 

 ■ Fundamental Gneiss Formation ' in South Africa," in 

 which he claimed that the gneisses of the Limpopo Flats 

 lorrcspond to the fundamental formation of the continent 

 of Europe, .^t the meeting three members contributed 

 viructural and niineralogical details from their own note- 

 books (Proc. for 1905, p. Ivii), recorded with an altogether 

 admirable clearness of expression. The full paper was 

 read on October 30, 1905 (Trans., p. 141). Dr. Voit 

 points out, in agreement with his predecessors, that the 

 main granite is intrusive in the Swaziland beds, " long 

 drawn out lenses of quartzite, chlorite, actinolite, and 

 other schists, swimming, as It were, in a granite magma." 

 But the Limpopo gneisses are, for him, still older, and 

 he looks forward to finding the granite intrusive in them 

 also. By the way, we must object to his using, on p. 145, 

 the term " interbedded igneous sheets " for intrusive 

 masses that have come up along planes of fracture in the 

 granitoid mass. On November 20 (Proc. for 1905, p. l.w) 

 the author sent in a letter in which he supported his views 

 by quoting Mr. -Anderson's observations in Natal, and on 

 December iS Messrs. Sandberg and Jorisscn made a reply 

 to Dr. Voit, in which Credner is cited as their authority, 

 in a manner that almost recalls the Wernerian discussions 

 of a hundred years ago. The bottom, if we may speak 

 Irreverently, is here knocked out of the " I'rgneissform- 

 .ntion " with considerable vigour, and the references to 

 ICiiropean literature, though disfigured by a few misprinted 

 pl.ice-names, add zest to a spirited discussion. 



Dr. Hatch, in his presidential address (Proc. for 190G, 

 p. xxv), refers to Dr. Voit's suggestion, and remarks that 

 the I,impopo gneiss may be only " a sheared or meta- 

 morphic portion of the granite." The address, on the 

 geological history of the South African formations, covers 

 ground on which much has been written, and on which 

 silence might now conveniently be preserved, until some 

 of the critical questions touched on can bo decided by 

 new and indubitable evidence. 



Mr. J. P. Johnson (Trans. Geol. Soc, S. -Africa, vol. 

 viii.. p. 135) describes and illustrates primitive stone 

 implements from the plateau of the Victoria Falls. Mr. 

 I.ainplugh directed attention to these (Report of Brit. 

 .Association for 1905, p. 300) as being possibly older than 

 the excavation of the Batoka Gorge, and Colonel Feilden 

 has .-ilreadv urged their importance upon the readers of 

 this Journal (Nature, vol. Ixxiii., p. 77). We trust that 

 we have said enough to show that geology in the best 

 sense, as a critical and comparative science, flourishes in 

 ihe dusty and inchoate city of Joh.innesburg. Probably 

 there Is no part of the world where geological phenomena 

 ]il.iv so l.-irge a pari In the Ihoughts of cultivated men. 



GRrNVII.I.E \. J. Coi-E. 



AliROyM'TICS AXD METEOROLOGY. 



"inHE fifth conference of the International Commission 

 of .Scientific .Aeronautics was held at Milan, and com- 

 menced its sittings on October i. The conference was 

 formallv opened bv Prof. Celoria, representing the com- 

 mittee of the Milan Exhibition, M. Gavazzi, representing 

 the municipality. Prof. Palazzo, and Prof. Hergesell, 

 president of the commission. 



-A large number of representatives attended the con- 

 ference ; Mr. Dines represented the Meteorological Office, 

 and the other English members were Major Baden-Powell, 

 Mr. Patrick .Alexander, and Mr. Charles Cave. 



The first meeting for the di.scussion of scientific ques- 

 tions was held in the afternoon of October i under the 

 presidency of General Rykatchew and Prof. Palazzo. Prof. 

 Hergesell read his report, and various questions were dis- 

 cussed' relating to the business of the conference. In the 



evening the committee of the exhibition entertained the 

 members of the conference at dinner. 



On October 2 the members went to Pavia, where ^L 

 (Jamba showed them over the observatory, and liberated 

 two haUotis-sondcs. -After visiting the university the 

 members were entertained at luncheon by the municipality 

 of the town. 



The second meeting was held on October 3 under the 

 presidency of Prof. .Assmann and M. Teisserenc do Bort. 

 Dr. Erk urged the necessity of making ascents in the 

 neighbourhood of the Alps for studying local phenomena, 

 such as the F'tihn. M. do Quervain explained a method 

 of using small pilot balloons for determining the winds at 

 different altitudes ; small india-rubber balloons were 

 liberated and watched with a theodolite ; assuming that 

 the balloon ascended with uniform velocity, it was possible 

 to determine its course from one station. Prof. Hergesell 

 spoke very highly of the method which he had used at 

 Strasburg and elsewhere, and mentioned that in Spits- 

 bergen he had watched the balloon to a distance of 80 kilo- 

 metres. M. Ebcrt explained his method of determining 

 the deformation of the electrical ecjuipotential surfaces in 

 the neighbourhood of a balloon, and exhibited a new 

 apparatus for measuring the ionisation of the air. 



The third meeting was held in the afternoon of October 3 

 under the presidency of Colonel Vives y Vich and Mr. 

 Cave. General Rykatchew and M. Riabouschinsky read 

 the reports of the work of their observatories. M. de 

 Quervain read a paper on the thermal inertia of therino- 

 meters used in kite and balloon ascents. In connection 

 with this an important discussion took place on the relative 

 value of ballons-sondcs and kites for the study of the air 

 up to 5000 metres or so. Prof. Hergesell strongly advo- 

 cated the use of balloons in preference to kites ; General 

 Rykatchew and M. Berson thought that kites were far 

 more suitable. 



Mr. Rotch read a paper on the ascents of hallons-sondes 

 in America, and General Rykatchew read a paper on the 

 temperature gradient as observed at Pavlovsk. 



Prof. Hergesell explained a method of recording vertical 

 movements in the atmosphere by attaching a " log " to 

 balloons. M. de Quervain gave proofs of the reality of 

 the isothermic zone. 



In the morning of October 4 the members visited the 

 aeronautical section of the exhibition, and hallons-sondes 

 were liberated by M. Gamba, M. Teisserenc de Bort, and 

 Prof. Hergesell. In the afternoon the fourth meeting was 

 held under the presidency of .Mr. Rotch and M. Scheimpflug. 

 General Rykatchew described M. Kouznetzow's method 

 of determining the height of clouds at night by means of 

 a .search-light, and gave some of the results obtained at 

 Pavlovsk. M. Koppen, M. Teisserenc de Bort, and Mr. 

 Rotch observed that the method had been used at Ham- 

 burg, in France, and in America. Mr. Alexander read a 

 communication on the forms of propellers for flying 

 machines. 



M. Moedebeck urged the necessity of having descriptive 

 charts for aeronautical purposes that would show, for 

 example, dangerous places such as those where there were 

 wires carrying currents at a high potential. M. Scheim- 

 pflug gaye an account of his method of making maps from 

 photographs taken from balloons. M. Teisserenc de Bort 

 read a report on the necessity of extending the number of 

 stations at which ascents are made, and Prof. Hergesell 

 said he would make every effort to carry out this sugges- 

 tion. Prof. Palazzo said he hoped that he would shortly 

 be able to establish a kite station on Mount Etna. M. 

 Hinterstoisser then gave a lecture on aeronautics from the 

 points of view of science and sport, and illustrated it with 

 lantern-slides. 



On Friday, October 5, M. Mangili, president of the 

 committee of the exhibition, entertained the members in 

 an excursion by steamboat on the Lago Maggiore. It had 

 been proposed to make kite ascents, but this proved 

 impossible owing to want of wind. Prof. Hergesell 

 attempted to demonstrate his method of dropping hallons- 

 sondes at sea. I'nfortunately his apparatus had not 

 arrived, and the hallon-snnde sent up did not come down as 

 soon as was intended, and was last seen at a great height 

 and still ascending. 



NO. T93O, VOL. J/C 



