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ARTICLE XX. 
An Account of the Magnetic Observatory and Instruments at 
Munich: extracted from a Memoir entitled ‘ Ueber das Mag- 
netische Observatorium der Kénigl. Sternwarte bei Miinchen, 
von Dr. J. Lamont, Director of the Observatory. 
(DR. Lamont’s memoir commences with a review of the early 
history of our knowledge of terrestrial magnetism ; after speak- 
ing of the discovery of the declination, and of its secular, annual, 
and diurnal changes, it notices that besides these more regular 
‘movements, there are others, which may be subdivided into,— 
movements of greater magnitude, resembling tempests of the 
atmosphere, felt simultaneously at distant places, and which may 
perhaps be connected with other phenomena of occasional occur- 
rence and remarkable character,—and into movements of lesser 
magnitude, more transitory in their nature and occurring more 
frequently, but which are equally unamenable to any known laws. 
It then proceeds as follows] :— 
The latest recognised and not yet completely known peculi- 
arity relates to the different manifestation of the magnetic force 
in different parts of the earth’s surface. The results obtained 
by single observers, and by numerous expeditions of discovery 
by sea and land, have pointed out a system in this respect, cer- 
tainly resting upon laws, though not apparently connected with 
the form, or peculiarities of the surface, of the globe. They 
have also indicated in respect of time, a progressive movement 
of the whole system towards the east*. By virtue of this latter 
movement the relations observed in these countries two centuries 
ago have now almost reached the limits between Europe and 
Asia, whilst other parts of the system have gradually moved 
over to us from the westward. The cause of this singular phee- 
nomenon is the more difficult even to conjecture with probability, 
because in the whole compass of our knowledge concerning the 
forces acting on the surface of the earth, we know of no analo- 
gous fact. 
The results thus generally indicated and referred to pointed to 
* Dr. Lamont here refers to the movement in the northern hemisphere : the 
corresponding movement in the southern hemisphere is towards the west.—E. S. 
