652 



SGIENGE. 



[N. S. Vol. XI. No. 278. 



tions simultaneously at stated periods, for 

 the purpose of deducing laws governing the 

 complex phenomena of the earth's magnet- 

 ism, and to recognize harmony in irregu- 

 larities apparently subject to no law. 



Almost every civilized country has either 

 just completed a magnetic survey, or is 

 taking the necessary steps for the inaugura- 

 tion of such work on a grander and more 

 comprehensive scale than ever before. The 

 writer remarked this especially during his 

 recent visit at foreign observatories, under- 

 taken for the purpose of comparing a set of 

 the U. S. Coast and Geodetic Survey instru- 

 ments with the Observatory Standards. A 

 veritable boom in magnetic work seems to 

 have set in. Thus Eschenhagen, in charge 

 of the magnetic work of the Prussian 

 Meteorological Institute is conducting a 

 magnetic survey of Prussia. Captain Den- 

 holm Fraser, of the Koyal Engineers of 

 England, is at present actively engaged in 

 making the necessary arrangements for in- 

 augurating a detailed magnetic survey of 

 India and Burma. Captain Lyons, of the 

 Royal Engineers, in charge of the Geological 

 survey of Egypt, who has for some years 

 been making magnetic observations during 

 his journeys in various parts of Egypt, is 

 now planning to make a systematic survey 

 of that country. 



The Australasian Association for the Ad- 

 vancement of Science at its Sidney meet- 

 ing in 1898, on the recommendation of 

 Section A, created a committee for the pur- 

 pose of promoting the study of Terrestrial 

 Magnetism in the Australasian colonies, 

 and passed a resolution ordering the New 

 Zealand Government, in particular, to es- 

 tablish a permanent magnetic observatory 

 in that colony, and subsequently to initiate 

 a general magnetic survey. The Secretary 

 of the Committee, Mr. C. Coleridge Farr, 

 was very energetic and persistent in arous- 

 ing the New Zealand people to take an in- 

 terest in the matter, and the consequence 



was that the New Zealand Government 

 passed a vote of 500 pounds sterling towards 

 the establishment of a permanent station. 

 Mr. Farr is at present making the prelim- 

 inary arrangements for the establishment 

 of a magnetic observatory and for the in- 

 auguration of a magnetic survey. 



As another result of the 1898 meeting 

 of the Australasian Association, the Mel- 

 bourne Observatory has been granted funds 

 for reducing the magnetic records of the 

 past thirty years. It is extremely fortu- 

 nate for the advancement of science of Ter- 

 restrial Magnetism in this part of the globe 

 that such an energetic and enthusiastic in- 

 vestigator as P. Baracchi is at the head of 

 the Melbourne Observatory. 



There have been recently established new 

 magnetic observatories at the following 

 points : Munich, Germany ; Genoa, Italy ; 

 Mexico City, Mexico. The important ad- 

 vance that this country has made to- 

 wards setting on foot a detailed magnetic 

 survey of our dominions and for the erec- 

 tion of the necessary observatories has al- 

 ready been described. 



With these few prefatory remarks, I will 

 now briefly mention a few of the important 

 recent contributions to our knowledge of 

 Terrestrial Magnetism. 



The theoretical investigations of Dr. Adolf 

 Schmidt of, Gotha, Germany. — Di'. Schmidt 

 has just completed an elaborate harmonic 

 analysis of the earth's permanent mag- 

 netic field. His investigations are, in a 

 certain sense, an amplification and an ex- 

 tension of Gauss's great work entitled ' The 

 General Theory of the Earth's Magnet- 

 ism. ' Many investigators fail to see that 

 Gauss's investigations elaborated &nj theory 

 of the earth's magnetism and the question, 

 " What is Gauss's theory of the earth's 

 magnetism?" may, therefore, deservedly 

 occupy our attention for a few minutes. 

 Were I asked this question, I would re- 

 ply as the lamented Herz did in his book 



