ON TERRESTRIAL MAGNETISM AND ATMOSPHERIC ELECTRICITY. 745 



Dar-es-Salam bereits projectirten Observatorien den gegenwiirtigen 

 ungeniigenden Zustand verbessern. Auf der siidlichen Halbkugel 

 miissten ausser den bereits projectirten Observatorien in Santiago de 

 Chile und La Plata noch ein Observatorium am Cap der guten Hoffnung 

 und ein anderes wo moglich auf einer der Inseln St. Paul oder N. 

 Amsterdam begriindet werden. Die Subkommission empfiehlt somit, 

 ausser den bereits friiher projectirten, bestandigen Observatorien, sich. 

 fiir die Begriindung folgender temporarer Observatorien zu verwenden : 



1. Taschkent Russian d. 



2. Peking China. 



3. Lick-Observatorium .... Vereinigte Staaten N. A. 



4. Quito Ecuador. 



.5. Para ....... Brasilien. 



G. Colombo Anglo-Indien. 



7. Cap der guten Hoflfnung . . . England. 



8. -St. Paul oder N. Amsterdam . . . Eine der grossen Seemachte, 



z. B. Frankreich. 



Den hier aufgezahlten soUte sicb wenigstens noch ein Observatorium 

 in hoheren siidlichen Breiten anschliessen, sei es auf den Falklandsinseln, 

 auf Kap Horn oder an einem anderen in diesen Breiten gelegenen 

 Punkte. 



Im Hinblick auf die Schwierigkeiten, welche die Errichtung gerade 

 dieses Observatoriums bieten wird, schien es jedoch richtiger, keinen 

 bestimmten Vorschlag zu machen, sondern zunachst nur eine allgemeine 

 Anregung zu geben. 



After considering this report the Permanent Committee passed the following 

 resolution : — ' That it is desirable that temporary magnetic observatories should be 

 established in places such as the following: — Taschkent, Peking, the Lick Ob- 

 servatory, Quito, Para, Colombo, Cape of Good Hope, St. Paul or N. Amsterdam, 

 Honolulu, and Point Barrow or Sitka, or some other station in a high latitude in 

 North America. 



' 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 sunspot period.' 



2. The Application of Terrestrial Magnetism to the Solution of some 

 Problems of Cosmical Physics. By Arthur Schuster, F.R.S. 



In dealing with a subject in which a great part of the work is purely statistical, 

 it is always advisable to keep in mind the real problems which form the ultimate 

 object of the statistical inquiry. It may be of interest, therefore, to the Congress 

 to have a short summary of what 1 consider to be the most pressing questions of 

 cosmical physics on which the science of terrestrial magnetism may throw some 

 light. 



We know that the greater part of the magnetic forces which we observe on 

 the surface of the earth are due to inside causes, but our information is barely 

 sufficient at present to decide whether an appreciable portion, possibly amounting 

 to 5 per cent, of the whole, may not have an outside origin. The outside forces 

 must be divided into two diflFerent types, according as they are stationary in space 

 or revolve with the earth. Stationary outside forces may be due to magnetic 

 effects of the sun or moon, or generally to magnetic induction in that part of space 

 through which the earth moves. A magnetism fixed in space would give rise to a 

 Tariation having the sidereal day for period, and if the force is of solar origin 



