Omaha daily bee., 1899-10-01

e~xtremities corresponding to the north and
south poles of the earth. The magnetic in
fuence of the sun and moon penetrating the
earth's surface and the molten sea reaches
the magnetic nucleus whose movements they
control. But the revolutions. Of the nu-
cleus do not exactly correspond to those OF
the earth, he thought. They follow the d.
rection Of the sun and moon from east to
west. This counter movement accounts for
the difference between the geographical AM
magnetic poles OF the earth.
The molden sea within the earth, Lieu
tenant Schultze believed, has its tides the
same as the oceans ON the surface and as
they rise and fall they act upon the earth in
a contrary direction, thus retarding the crust
on it's eastward sweep. The crust makes one
revolution more than the molten sea and
thus another influence appears to disturb the
magnetic equilibrium. The magnetic fluc-
~tuations are greater in summer than in
winter. But many scientists disagree with
Schultze and so no one is entirely certain
of the phenomenon's cause.
What the Chart Means.
1t lis this secular variation Of the needle
which makes it necessary to reconstruct
~isogonic charts and change the compasses
and magnetic bearings on the charts. An
error in calculation by a navigator based
I hpOi laB iRIOo NhuI haNo - huy
easily cause a wreck and for this reason the
geodetic and coast survey issue new charts
at regular and frequent periods and every
captain is provided with them.
To property holders the shifting of the
magnetic meridians may mean much. At
the present time most surveyors base their
calculations upon the geographical merid-
ions, but IN former times the lines were
based upon the magnetic meridians. From
this arise many discrepancies and n surveyor
when making a survey of old property Is
obliged to ascertain the old calculations in
order that his survey may correspond to the
former one, else he may make al error that
will result in injustice and perhaps long and
costly litigation. Disputes of this character
continually arise and the court of last resort
is always the geodetic and coast survey,
which is usually able to settle the contro-
versy.
The desirability of regular and systematic
century by Humboldt. who said they should
be made every twenty-five years.
The Men in Charge. p
The present survey is under the general
direction of Professor Henry S. Pritchett,
superintendent of the geodetic and coast
survey, but 1t will be actively directed by
Assistant Superintendent Charles A. Schott.
Mr., Schott has been connected with the
bureau since 1S4S and is the leading author
ity in this country on all subjects connected
with terrestrial magnetism. His series Of
essays and tables of secular variation issued
annually In three reports OF the geodetic and
coast survey for a number of years past are
the standard works OF the kind. AS he has
given his life to the study OF that branch
OF science and has been mainly instrumental
In n1IrSuadinp tha cnvar,n nant 20 ,,,aon4at,o
the work of recharting the magnetic merid-
ians it Is certain to be done scientifically and
thoroughly and 1t will be Invaluable for all
time to come.
Closely associated with Mr.. Schott in this
labor is Prof. l.. A. Bauer, chief of the
bureau of terrestrial magnetism. Prof.
Bauer Is enthusiastic and says the amount
of money that will be saved to landowners
alone by the survey will greatly exceed is
cost.
AS a preliminary step toward obtaining
data on land for the survey llS stations have
been established in the east, and other sta
tions will be added as they are required
All observations will be compared with
similar observations to be made in foreign
countries.
How IL VIII he Done.
THE United States" says Prof. Bauer,
lin outlining the plans OF the survey, covers
as much ground as Europe, or one-hfteenth
OF the land area OF the globes, 612, ITO
square miles. Great Britain had one sta
ton TO every 1879 square miles; Holland,
one for every forty square miles; II We
decide on one for every 100 square miles it
would require 10000 stations for the United
States. At the rate Of 400 stations a year
1t will take seyenty-hye years to complete
the work. But ten years is desirable, BY
the end OF the year 1910 We shall have COW
cred 1000 stations. We will first make a
magnetic survey OF the country with sta
tions twenty-five or thirty miles apart, and