September 15, 1898] 



NATURE 



475 



meeting, more especially for the discussion of its report to the 

 International Meteorological Conference. It is evident that 

 here there is plenty of opportunity for collision between rival 

 authorities, for confusion between conflicting jurisdictions ; but 

 to all questions as to the precise limits of authority and juris- 

 diction it is sufficient to reply in the most general terms. The 

 whole of the arrangements are temporary, to meet an immediate 



f)ressing need. The work of the Conference will be conducted 

 ike that of a Department of the British Association. The 

 members of the International Committee will act as the Com- 

 mittee of the Department, but some of their work will be done 

 on the General Committee of Section A, of which other 

 magneticians will also be members. Should it be necessary, 

 they will hold some separate meetings, and some such meetings 

 will certainly be necessary to discuss their report to the 

 International Meteorological Conference. These general regu- 

 lations will probably suffice for all practical purposes. If cases 

 occur which they do not cover, we must deal with them as they 

 arise. 



With regard to the future, I do not propose to lay before you 

 any detailed scheme, but in discussing the matter among 

 ourselves, the following principles should, in my opinion, be 

 adhered to. The International Meteorological Conference has 

 held a number of successful meetings. I believe that I am 

 correct in saying that the right to attend that Conference was at 

 first confined to those who were officially connected with 

 Meteorological and Magnetic observatories, but that of late 

 invitations have been more widely distributed. If the authori- 

 ties of that Conference see their way to inviting in future most 

 or all of those who are known to be specially interested in 

 Terrestrial Magnetism, I do not see why the Magnetic Con- 

 ference, which would then be constituted once in five years, 

 should not meet all our requirements. If, however, additional 

 meetings are necessary, I would urge that they should be held 

 in turn in different countries, and, if possible, in connection with 

 existing societies which play elsewhere the part taken by the 

 British Association in this country. 



That a permanent committee should be established is essential, 

 and the mode of appointing this body must no doubt be con- 

 sidered, but I hope that in the course of the next few days the 

 committee may be able to discuss the whole question, and that 

 when the next meeting of the Meteorological Conference takes 

 place we may be able to lay before the Committee suggestions 

 which may lead to the foundation of an International Magnetic 

 Association on a stable and permanent basis. 



Another matter of great importance is the maintenance of an 

 international journal devoted to Terrestrial Magnetism. This 

 we now possess, thanks to the energy of Dr. Bauer, and I feel 

 sure that all present will agree that such a means of intercom- 

 munication is invaluable. I believe, however, that the enter- 

 prise is threatened with financial dangers, and I desire to take 

 this opportunity of urging all those who are interested in its 

 success to do what they can to support it by increasing the cir- 

 culation. There is every reason for making more use of a 

 common journal. The records of the observatories are neces- 

 sarily so bulky, that any one who desires to obtain the facts as 

 to the magnetic state of the earth at any given time must collect 

 or consult a large library of quarto volumes, in some of which 

 the magnetic facts are mingled with data interesting chiefly to the 

 meteorologist or astronomer. It is no doubt essential that an 

 account of all the work done at each observatory should be 

 published in a collected form, and that full details of the magnetic 

 observations should be given ; but for many, nay, for most, 

 purposes, those who use the records will require only final 

 results ; the means of the various elements for the year, for 

 each month, or for any other period which may hereafter be 

 adopted, and the mean diurnal variation, are in general wanted, 

 rather than the hourly values. If these means could be 

 published together, once a year, an enormous boon would be 

 conferred upon magneticians. For special purposes the theorist 

 will have to test his views by reference to the results published 

 in their fullest detail ; but it would be no slight gain if the more 

 salient facts could be compared by being placed side by side in 

 the same journal. One advantage such a system would un- 

 questionably possess. It would impress upon the authorities of 

 the observatories the necessity for adhering to a common form 

 of publication. 



Some small beginnings have already been made. The Kew 

 Observatory Committee now publish in the Proceedings of the 



Royal Society the annual means of the elements recorded by 

 all the observatories which send their publications to Kew. By 

 comparing two of these tables, the secular change can at once 

 be determined. But the system is capable of extension, not 

 merely to the normal values of the elements, but to disturbances. 

 By common agreement, Greenwich and Pare St. Maur publish 

 in each year the records of the same magnetic storms. If this 

 agreement could be extended, and if the facts thus selected 

 were brought into juxtaposition, we might hope for a fuller and 

 more instructive analysis than is at present usual. 



Turning from questions of organisation, the primary business 

 of our conference will be to discuss four questions submitted to 

 our Committee by the International Meteorological Conference. 



The first two of these refer to the methods for calculating and 

 publishing the monthly means of the magnetic elements which 

 should, in our opinion, be adopted. I will not anticipate the 

 discussion which will take place on these points, except to say 

 that it will be necessary to bear in mind not only what is 

 desirable, but also what is practicable in view of the resources 

 at the disposal of the directors of the various magnetic observ- 

 atories. 



Another question deals with the relative merits of long and 

 short magnets, and on this point we shall have the advantage of 

 hearing a report on the subject by M. Mascart. 



Lastly, there is a very important proposal for the establish- 

 ment of temporary magnetic observatories at certain specified 

 places. General Rykatcheff and Prof, von Bezold present ai> 

 excellent report on this subject, and I will only remind you 

 that whereas the accuracy of the mathematical expression of the 

 magnetic state of the earth's surface depends entirely on the 

 number and position of the spots at which the magnetic 

 elements are accurately known, the establishment of temporary 

 observatories will be a costly undertaking, for the carrying out 

 of which all the resources at the disposal of international science 

 will have to be employed. 



Another point of considerable practical importance will also 

 be brought before us. The rapid extension of electrical rail- 

 ways and tramways is a serious menace to magnetic observ- 

 atories. From all parts of the world we hear of observatories 

 ruined or threatened by the invasion of the electrical engineer. 

 Toronto and Washington have already succumbed ; Potsdam, 

 Pare St. Maur, Greenwich, and Kew are besieged, and the issue 

 largely depends upon whether these great national observatories 

 can or cannot make good their defence. 



It seems to be a law of nature, ruling alike the human race 

 and the humblest microbe, that the products of an organism are 

 fatal to itself. The pessimist might infer that we are in presence 

 of another instance of the universality of the application of this 

 law, and that pure science is threatened by the very success of 

 its practical applications. The smoke of our cities blots the 

 stars from the vision of the astronomer, who, hke the 

 anchorites of old, flies from the world to mountains and 

 desert places. It is only in the small hours of the morning 

 when 



" Save pale recluse, for knowledge seeking, 

 All mortal things to sleep are given," 



that the physicist can escape from the tremors of the traffic of a 

 great town. 



Civilisation as it spreads by aid of the means that science has 

 placed at its disposal is destroying records, and obliterating 

 boundaries by the study of which the anthropologist and the 

 biologist might have read far back into the history of our race. 

 And now in turn the science of Terrestrial Magnetism, which, 

 on the one hand, is forging another link to connect the sun 

 and earth, and, on the other, is penetrating within the surface 

 of the globe to depths beyond the ken of the geologist, is 

 threatened by the artificial earth currents of the electric 

 railway. 



That the crisis is serious there can be no doubt, but I will 

 only anticipate the fuller discussion which will take place by 

 stating that magneticians, in common with the rest of the world, 

 recognise the great benefit which electric traction confers upon 

 the community at large. We are not so foolish as to desire to 

 embark on a crusade against a great industrial improvement of 

 which science may well be proud ; on the other hand, we must 

 hold fast to the position that provision for the conveniences 

 which are immediately appreciated by the public should be made 

 with as little damage as possible to those studies which are not 

 less for the ultimate lienefit of the race. 



NO 1507, VOL. 58] 



