November 3, i8y8] 



NATURE 



19 



" That these observatories should, if possible, be provided 



with both absolute and variation instruments, of which 



the latter should be self-registering instruments, and 



should be established for at least seven, and if possible, 



for eleven or twelve years, i.e. for a complete sun-spot 



period." 



The Committee were informed by Dr. C. Schott that it was 



the intention of the Coast and Geodetic Survey of the United 



States to establish a magnetic observatory at Honolulu. 



In the course of the discussion on the above resolution, the 

 Committee also resolved : — 



(3a) " That it is desirable to point out that observatories at 

 great distances from others should be provided with both 

 absolute and self-registering variation instruments." 



(4) The fourth matter referred to the Committee was the 

 question as to the relative advantages of long and short 

 magnets, raised by M. Mascart at the Paris Conference (Report, 

 p. 39)- 



On this subject a report, of which a copy is appended, had 

 been prepared, at the request of the President, by M. Mascart. 

 After considering this report, the Committee resolved : — 

 " Unless special reasons e.xist to the contrary it is desir.ible 

 that the dimensions of the magnets should be as small as 

 possible, provided that the accuracy of the results is 

 adequately maintained." 

 (h) Resolutions passed by the Committee on matters arising 

 during the International Conference. 



(5) Prof. Eschenhagen made a statement to the Conference 

 as to his recent investigations on minute disturbances made by 

 very sensitive apparatus with a very open time scale. 



In view of this statement, the Committee expressed their 

 sense of the importance of the resolutions on this subject passed 

 by the Paris Conference (Report, p. 35), and the hope that the 

 principal observatories would carry out simultaneous observ- 

 ations of the character proposed. 



M. Moureaux informed the Committee that preparations for 

 such observations were already complete in the observatory at 

 Pare St. Maur. 



The Committee took note of the statement that Prof. 

 Eschenhagen would be willing to give information as to the 

 construction of the instruments used l)y him. 



(6) The Committee also passed the following resolution : — 



" The Committee is of opinion that tlie early establishment 

 of a magnetic observatory at the Cape of Good Hope, 

 provided with absolute and self-registering variation 

 instruments, would be of the highest utility to the science 

 of Terrestrial Magnetism, especially in view of the 

 Antarctic expeditions which are about to leave Europe, 

 and that the observatory should be established at such a 

 distance from electric railways and tramways as to avoid 

 all possibility of disturbance from them." 

 Directions were given that the proper steps should be taken 

 to obtain the approval of the British Association for this 

 resolution, with the request that, if approved, it should be for- 

 warded to the Colonial Government. 



(7) On the motion of Prof. Adolph Schmidt, the Committee 

 resolved : — 



" That it is desirable that magnetic observations taken in 



regions not included in a magnetic survey, should be 



repeated from time to time, care being taken to secure 



the identity of the point of observation." 



(S) Prof. Eschenhagen was requested to draw up a detailed 



scheme for the exchange between the various observatories of 



the curves of the self-registering variation instruments taken 



during important magnetic storms, and to lay the scheme before 



the next meeting of the Conference. 



(9) With reference to certain inquiries which Prof. Eschen- 

 hagen suggested should be addressed to the Directors of 

 Magnetic Observatories, the Committee was of opinion that, 

 although it would be outside the scope of their duties to make 

 the inquiries, it was desirable that the information should be 

 collected and published. 



(10) After the discussion on the magnetic disturbances intro- 

 duced by electric railways and tramways, the following resolution 

 was adopted by the Committee : — 



" The Committee are of opinion that any sensible magnetic 

 disturbance produced in a magnetic observatory by 

 electric railways or tramways, is seriously detrimental 

 and may be fatal to the utility of the observatory. They 

 consider that special precautions should be taken to 



NO, I 5 14, VOL. 59] 



prevent such disturbances, and append as an example the 

 provisions for the protection of the Kew Observatory, 

 inserted in a Bill passed by the British Parliament 

 authorising the construction of an electric railway, the 

 nearest point of which is to be at a distance of one kilo- 

 metre from the observatory (Appendix II.)." 



Ftilure Organisation of the Committee. 

 (10) The Committee took into consideration their own future 

 organisation, and passed the following resolutions : — 



" It is desirable that terrestrial magnetism should continue 

 to be within the scope of the International Meteorological 

 Conference, provided that : — 

 (a) Invitations to attend that Conference are issued as 

 widely as possible to Directors of Magnetic Observatories 

 and to all students of Terrestrial M.agnetism. 

 [h] That the Permanent Committee on Terrestrial Mag- 

 netism and Atmospheric Electricity, as established at the 

 Paris Conference, be continued. 

 (i) That in future there shall be a magnetic section of the 

 International Meteorological Conference, which shall 

 elect, or otherwise share in the appointment of, a 

 permanent Magnetic Committee. 

 (d) That the Magnetic Committee have power to summon 

 an International Magnetic Conference at times other 

 than those at which the whole of the International 

 Meteorological (and Magnetic) Conference may meet." 

 The Committee also consider that the President of the Per- 

 manent Magnetic Committee should hold office between two 

 successive meetings of the International Meteorological (and 

 Magnetic) Conference. 



(Signed) Arthur W. RiicKER, President. 

 September 13, 1S98. 



Appendix II. 

 Clause for the protection of Kew Observatory, 

 (i) The whole circuit used for the carrying of the current to 

 and from the carriages in use on the railway shall consist of con- 

 ductors which are insulated along the whole of their length to 

 the satisfaction in all respects of the Commissioners of Her 

 Majesty's Works and Public Buildings (in this section called 

 " the Commissioners"), and the said insulated conductors which 

 convey the current to or from any of such carriages shall not at 

 any place be separated from each other by a distance exceeding 

 one hundredth part of the distance of either of the conductors 

 at that place from Kew Observatory. 



(2) If in the opinion of the Commissioners there are at any 

 time reasonable grounds for assuming that by reason of the 

 insulation or conductivity having ceased to be satisfactory a 

 sensible magnetic field has been produced at the observatory, 

 the Commissioners shall have the right of testing the insul- 

 ation and conductivity upon giving notice to the Company, who 

 shall afford all necessary facilities to the engineer or officer of 

 the Conmiissioners or other person appointed by them for the 

 purpose, and the Company shall forthwith take all such steps as 

 shall in the opinion of the Commissioners be required for 

 preventing the production of such field. 



(3) The Company shall furnish to the Commissioners all 

 necessary particulars of the method of insulation proposed to 

 be adopted, and of the distances between the. conductors 

 which carry the current to and from the carriages. 



APPLICATIONS OF ELECTRICITY.'' 

 Lightning. 

 ""PHE first practical application of the science of electricity was 

 -*- for the protection of life and property. Franklin in 1752 

 showed how to secure ourselves and our buildings from the 

 disastrous effects of a lightning stroke. Very little has been 

 done since to improve upon his plan. A Lightning-Rod Con- 

 ference, upon which I served, met in 1S7S, and its report, 

 published in 1881, remains an admirable and useful standard of 

 reference. The principle advocated by Franklin was preven- 

 tion rather than protection. If a building or a ship be fitted 

 and maintained with good continuous copper conductors, 

 making a firm electrical contact with the earth or the sea, and 



1 Abridged from 

 Civil Engineers, on 

 C.B., F.R.S. 



ugural address delivered at the Institution 1 

 nber i, by the President, Mr. W. H. Preio 



