The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1892-02-19
THE MAGNETIC NORTH.
The Earth's Interior in Liquid state and
Rotating Independently of the Outer
Shell,
New York Tribune,1


just why the magnetic needle, instead
of pointing due northward, inclines to
one side to a greater or less degree, and
why the region toward which tits di-
rected keeps shifting slowly, is problem
which has for ages baf1ed the wisest men
But solution of it which, if it is not &C
cepted by the scientific world as COM
plete and final, at least has much to com
mend it to instant favor is now offered
by Henry Wilde, f. G. S. 1t is briefly
discussed in The American Meterorologi-
cal Journal for january by that new,
though already eminent, authority on
Terrestrial Magnetism, Professor Frank
III. Bigelow.
Mr.. Wilde has come to the conclusion
that the onter shell of the earth and the
great mass within rotate somewhat indie
pendently of each other. The interior
portion, still in a liquid condition, he
conceives is continuing to revolve about
the axis which our planet had in it's in
fancy; that is, one perpendicular to the
pldl1O VI UuO COllpUlOs ROI1CuCW3 Ill UAiO
great cataclysm in which the moon was
thrown off from the earth, the crust of
our globe was, he thinks. skewed over to
one side about twenty-thr se degrees; and
this part of our sphere, therefore, re-
wolves about what we call 'the geogra-
phical pole" The inner mass, like the
other planets and the sun, he regards as
electro-dynamic; while the shell is cleo
4..1 i,
are supposed to render those portions of
more highly magnetic than others; the
permanent low temperatures at the bot
tom of the ocean and the greater amount
of iron here included, the crust being
thicker under the seas than elsewhere.
For purposes of demonstration Mr..
Wilde constructs a machine consisting of
one sphere within another slightly larger
one, both converted into magnets by
coils of wire encircling them. Upon
those portions of the shell which CORES
pond to the oceans he attaches mag
netized sheet iron. And by means of
proper gearing he makes the inner and
outer spores rotate on axes 231 degrees
apart. Finally, for test purposes, he
provides for temporarily fixing mag
net1c needle at any point on the surface
of the globe. With this ingenious appar-
atus, he declares he can reproduce
every known variety of intensity and
direction in terrestrial magnetism
and, what is the convincing fea-
ture of his experiment, the real magnetic
history of all parts of the world for the
last four centuries, so far as he can learn
it, is actually repeated in the minutest
details when the inner sphere is made
to fall behind the other one, in their
revolution. at the rate of 223 minutes of
an arc annually! That exceedingly we'll
informed and cautious expert, DR..
Charles A. Schott, of the United States
coast and goedetic survey, tells Professor
Bigelow that he has records of magnetic
variations of which MI Wilde is evident
ly ignorant; and that when these are
used as tests, in addition to the vast num-
Der of notifications which MI. Wilde has
presented, the theory still holds good.
The period of time here required for one
whole secular change is $50 years,
which agrees with the values of Sir Will
liam Thomson, though differing some
what from tradition.
The only doubt which will remain in
any scientific mind regarding the sound
ness of Mr.. Wilde's explanations, after
studying this magnificent demonstration,
will probably spring from the notion,
now widely entertained by physicists,
that the earth is solid to its core. Sir
William Thomson has expressed the be-
lief that the whole globe is as rigid as
glass, if not as firm as steel. Yet Mr..
Wilde declares himself thus confidently:
From the various movements of the de
clination and inclination needles, CORE
lated with each other in direction, time