i8 



NA TURE 



[November 3, i< 



THE INTERNATIONAL CONFERENCE ON 

 TERRESTRIAL .UAGNETISM. 



AAf E publish below the more essential parts of the Report of 

 '' the Permanent International Committee on Terrestrial 

 Macnetism. That report will, we believe, be submitted to the 

 Committee of the International Meteorological (and Magnetic) 

 Conference, to be held next summer in St. Petersburg, and may 

 be referred by them to the full meeting of the Conference to be 

 held in 1900 or 1901. The decisions arrived at will thus be fully 

 considered on several occasions, and will probably command 

 universal acceptance when they are finally approved. 



It is unnecessary to discuss in detail the four points which 

 were submitted to the Committee by the Paris Conference. 

 Two of these refer to the form in which the observations made 

 at observatories should be published. A third, based on a 

 report by M. Mascart, is, no doubt, intended lo crush the 

 curious superstition, w-hich still prevails, to the effect that the 

 larger the magnet employed to measure the magnetic elements 

 the more accurate will be the results attained. 



The fourth point referred to the Committee was of more im- 

 portance. The whole science of Terrestrial Magnetism is waiting 

 for more accurate knowledge of the magnetic state of the earth 

 in the tropics and the southern hemisphere. The Committee 

 propose that temporary observatories shall be established at sonje 

 dozen different places, most of which are easily accessible, and, if 

 possible, maintained during a sun-spot cycle. This can only be 

 done by international co-operation, and it is to be hoped that the 

 scheme may be carried out before long ; more especially as the 

 report on which the resolution was founded was jointly prepared 

 by General Rykatcheff and Prof, von Bezold, who hold high 

 official scientific positions in Russia and Germany respectively. 



The other papers read before the Conference were devoted to 

 various subjects which fairly covered the whole range of the 

 science. 



Prof. Adams' account of his brother's calculations on the 

 Gaussian constants, and Prof. Schuster's paper on a similar 

 subject, led to the remark that the mathematics of the subject 

 were at present far ahead of the accuracy of our knowledge of 

 the facts to which they are to be applied. 



The announcement made by Dr. Schott that a magnetic 

 observatory was about to be established in Honolulu, the sieps 

 taken by the Prince of Monaco to found an observatory in the 

 Azores, and the plucky start made by Dr. Beattie and Mr. 

 Morrison in a magnetic survey of South Africa, were sufficient 

 proof that efforts are being made to bring our experimental 

 facts to the standard our mathematics have attained. 



Local disturbances were dealt with in Sig. Palazzo's paper on 

 the neighbourhood of Etna, and in Captain Creak's interesting 

 statement as to the island of Funafuti. As our readers are 

 aware, this is the coral island on which boring operations have 

 been carried on for some time in order to test the rival theories 

 of the origin of atolls. The magnet has to a certain extent. 

 antici[->ated the results to be obtained by the drill. Indubitable 

 evidence has been found that the island is a centre of magnetic 

 attraction, and the magnitude of the vertical disturbance indicates 

 the presence of highly magnetic rock. It is, of course, possible that 

 this may exist at a depth which no boring could reach ; but the 

 result is certainly of interest with reference to the problem which 

 the boring is intended to solve. 



Drs. van Rijckevorsel and Bemmelen announced that their 

 elaborate survey of the Rigi had failed to establish any definite 

 connection between the magnitude of the magnetic elements and 

 height above the sea level. Earth currents were dealt with by Prof. 

 Schuster and Dr. Lemstriim. Dr. Schmidt utilised the occasion 

 to enforce the fact that isolated observations, made at irregular 

 intervals, at ill-defined positions, are of little use in the deter- 

 mination of the secular change ; while Dr. Eschenhagen pleaded 

 for the cooperation of other observers in the simultaneous 

 observation of the minute magnetic disturbances of which he is 

 virtually the discoverer. 



The Conference on the magnetic and electrolytic disturbances 

 produced by electric railways was not well attended by electrical 

 engineers, but the fact that .Mr. Preece and Prof. I'leming were 

 on the side of those who insist that these evils shall be dealt 

 with while they are still in their infancy, gives hope that the 

 bitter cry which is going up from directors of observatories, all 

 the world over, will not be unheeded. 



It only remains to add that the improvements in the organ- 

 isation of the I'crmanont Magnetic Committee, which were 



NO. I 5 14 VOL. 59J 



advocated by the President in his opening address, were adopted 

 by the Committee ; and that the Magnetic Section of the Inter- 

 national .Meteorological Conference will probably in future be 

 far more important than it has been in the past. 



Report of the Permanent Committee on Terrestrial 



Magnetism and Atmospheric Electricity to thb 



International Meteoroloc::cal Conference. 



Coiistilulion of the Committa. 



I. The Committee on Terrestrial Magnetism and Atmospheric 

 Electricity appointed at Paris in September 1S96, consisted of 

 eight members. These gentlemen found that it was desirable 

 to add to their number, by co-option, and the constitution of 

 the Commitiee is now as follows : — 



Appointed at Paris : Prof. Riicker (President), Prof. Eschen- 

 hagen, Prof. Liznar, M. Th. Moureaux, Sig. L. Palazzo, Dr. 

 Paulsen, Dr. van Rijckevorsel, General Rykatcheff^. 



Co-opted : Dr. Bauer, Prof. W. von Bezold, Sig. Brito- 

 Capello, Dr. Carlheim-Gyllenskjold, Prof. Mascart, Prof. T. 

 Mendenhall, Prof. A. Schmidt, Dr. C. Schott, and Prof. A. 

 Schuster. 



The report then proceeds to give an account of the proceedings 

 of the Conference at Bristol, which have been described in these 

 columns. 



II. Dr. C. H. Lees, of the Owens College, Manchester, and 

 one of the Secretaries of the Section of Mathematics and 

 Physics of the British .Association, acted as Secretar)' of the 

 International Conference and of the Permanent Committee. 



Meetings of the Permanent Committee. ^ 



III. During the session of the British Association, the ComW 

 mittee also held meetings on September 7, 9, 12 and 13, at 

 which the following resolutions were unanimously approved : — 



(a) Matters referred to the Committee by the International 

 Meteorological Conference. 



Four questions were referred to the Committee. 

 The first of these w.is the following resolution of M. Dufour 

 (Report of the Paris Conference, p. 30). 



" In calculating monthly means, all days are to be taken 



into consideration. It is left open to each Director to 



give, in addition, means calculated without taking 



disturbed days into account." 



This was approved by the Committee with the substitution of 



the words " It is desirable" for the words " It is left open to 



each Director." 



(irt) The Committee were also of opinion that the quiet days 

 chosen by the Directors of the different observatories should be 

 communicated to the President of the Permanent Magnetic 

 Committee, and circulated by him, and also that it is desirable 

 to inquire if it will be possible to select the same quiet days for 

 the diflferent observatories. 



(2) The second resolution referred to the Committee was the 

 following, proposed by Prof, von Bezold and M. Mascart 

 (Report, p. 31). 



" It is desirable to publish the monthly means of the com- 

 ponents X, V, Z, and at least for the months of January 

 and July, the differences dX, dV, dZ, of the hourly 

 means from the preceding means." 

 In lieu of this the Committee adopted the following resolu- 

 tion : — 



"It is desirable to publish the monthly means of the 

 Geographical Components of the Magnetic Force for 

 each month, and also the diflferences between the hourly 

 means for each month, and the monthly means for that 

 month." 



(3) The third resolution referred to the Committee was the 

 following, proposed by General Rykatcheff (Rep.irt, p. 32J. 



"It is desirable for the progress of Terrestrial .Magnetism 



that temporary observatories should be installed in certain 



localities, especially in tropical countries." 



On this subject a report had been prepared at the request o f 



the President, by Prof, von Bezold and General RykatchelT, of 



which a copy is appended. 



After considering the report the Committee resolved : — 

 "That it is desirable that temporary magnetic observatories 

 should be established in places such as the following : — 

 Taschkent, Peking, the Lick Observatory, tjuito. Para, 

 Colombo, Cape of Good Hope, St. Paul or N. Amster- 

 dam, Honolulu, and Point Barrow or Sitka, or some 

 other station in a high latitude in North .\merica." 



