82 F. H. Bigelow—The Earth a Magnetic Shell. 
such effects, must be found in the observations. The labor of 
computing the observations has heretofore delayed the produc- 
tion of such facts as will establish the existence of the polar 
field, to whose agency these important scientific conclusions 
have been attributed. 3 
_ The following schematic figure may assist to a clear concep- 
tion of the general relations that apparently exist in the space | 
surrounding the sun, at least to the distance of the earth. The 
Mitel be 
Schematic Figure of the Electro-magnetic and Magnetic Fields between the Sun 
and the Earth. 
electro-magnetic field E radiates from the sun in ail directions 
in straight lines, some of those near the ecliptic falling upon 
the earth; the magnetic field M fills all spaces with curved 
lines, the tube emanating from the polar regions of the sun, 
at 44° from its magnetic pole, falling upon the polar regions of 
the earth. The magnetic field at the earth has therefore three 
components, the so-called permanent magnetism, the field E 
and the field M. In Bulletin No. 2, U.S. Weather Bureau, 
1892, “ Notes on a New Method for the Discussion of Magnetic 
Observations,” my process for the separation of these three 
components was fully described and illustrated, the same having 
been used in all branches of the problem. It has also been 
shown that the visible coronal lines are other magnetic lines - 
of the field M, having their bases in two belts C G about 10° 
