Evening star., 1900-07-07

/
| Franklin bay northwest Of Greenland. saw
the same storm defect his needle more
| than twenty degrees. Frequently teleg
lines are interfered with by magnetic
storms, and 1t thus becomes impossible TO
| transmit messages while they are raging.
The instruments sometimes flash and shock
| the operators.
In August, 1894 a magnetic storm lasting
two days thus affected telegraph wires
running east and west. At the same time
| there occurred brilliant displays OF the
| aurora borealis. or northern lights DR..
Bauer tells me that there is an unQuestion-
able connection between sun spots and
magnetic storms. Every eleven or twelve
years old Sos face breaks out with a
| serious eruption At this same period the
aurora Is usually brightest and magnetic
storms are most numerous. The next sea-
son OF greatest sun spot activity will occur
In 1904. We may then anticipate severe
disturbances of the compass needle and
telegraph wire.
Machine Photographs Storm Waves.
To keep a Photographic record of all
Irregularities Of the magnetic needle, year
In and year out, will be the function OF one
OF DR.. Bauers automatic observers. This
consists Of metallic drum, having
wrapped around 1t sheet of paper like
that on which photographers print their
pictures. The drum is wound to revolve
once in twenty-four hours. A tiny search
light at the side projects a ray of light
onto small reflector fastened to a com
pass needle in front. This reflector throws
the ray of light upon the revolving paper,
where 1t falls as a small luminous spot
burning the paper black The slightest
movement by the compass needle turns the
reflector and causes the bright spot to
travel across the paper, thus leaving on
the latter complete record of it's jour-
ney. If the magnetic needle remains quiet
a whole day the black line on the moving
paper will be exactly straight. A magnetic
storm will cause the line to become all
Jagged a in RI
paper will enable the magnetician to esti-
mate the exact time when such disturb
ances nave occurred. In a SINH ar instru-
ment the compass needle will be balanced
to dip up and down on a horizontal pivot
and thus measure changes in currents
running in vertical plane. A third device
VIII contain similar dipping needle sus-
pended by pieces of quartz fiber. BY giving
thls nher twist the needle will be made
to rock up and down ike the walking beam
of a steamboat. The velocity of Its beat
timed through telescope. will measure
the intensity of the earth's magnetic pull
at the time.
Visitors Must DON Shoes
AS If entering a Mohammedan mosque
visitors at the projected observatory must
DON their shoes at the door This taboo
Will, however, apply only to footwear hav-
ing iron nails in the hee's. Before passing
the threshold guests must also remove all
IRON or steel buckles. buttons or clasps
from their garments and empty their pock-
cts of keys, knives or such articles liable
to attract the magnetic needles PEOPLE
with iron constitutions will be forbidden
ADMISSION. The magneticians employed at
the building will wear special clothing
1helr slippers Will be Sewed rather than
nailed at the soles and heels The auto
matte observers which DIR. Bauer lately
bought in Germany, are so sensitive IN
IRON or steel that small sewing needle
VIII distract them from their delicate work
Recently a sudden and serious magnetic
storm was indicated by the record of the
instruments now temporarily Installed in a
room OF the coast and geodetic survey.
Inc cause oil the phenomenon was traced
TO laborers who had been CARRYING iron
pipes through the building.
Trolley Car Storms.
The trolley car is the arch enemy of the
magnetcian. 1t is on this account that the
new standard observatory must be placed
sixteen miles out of town. The delicate
German instruments will show the effect
of trolley car movements eight miles away.
Were the observatory near an electric rail-
way system the instruments would daily ex-
perience a storm lasting from the time the
power house current was turned on in the
morning until turned off again at night
The kaiser has decreed that no electric
tramway shall be built nearer than twelve
miles to his magnetic observatory at Pots
dam. The car with the single trolley and
which lets the earth conduct the return
current creates much greater havoc than
that with the double trolley An electric
iway with the latter could operate with
in half-mie of the new observatory
without doing damage.
The three new observatories will from
time to time Issue maps showing the ma
riner and surveyor the exact changes
which have occurred in our magnetic cli-
mate. If the earth were a homogeneous
mass uniformly magnetized every compass
needle thereupon would point directly to
the north and south geographic poles By
astronomical instruments applied to the
other planets the magnetician learns the
true north and south line. He compares
this with the direction of his needle and
discovers its error. By repetition Of such
work all over the earth complete mag
netic survey of its surface will be made
Uncle Sam will contribute the data for
his land and sea dominions For the ocean
work he will employ complete magnetic
observatories placed aboard all-wooden yes-
sells Magnetic maps can then be drawn
to show the mariner surveyor just how
far he can trust his compass in any local
ity. Points where the magnetic needle reads
the same viii be connected by IRREGULAR
lines running north and SOUTH like those
of equal temperature on the weather map
such lines Will be constantly changing
with our magnetic climate Shipwrecks
have frequently resulted from these irreg-
ularfties as we'll as from magnetic storms
No end of trouble in the way of land
litigation and dispute has been caused by
this f1ckleness Of the compass. If a great
a
long, were placed upon our continent its |
points would move about ninety-two feet |
every twenty years. In other parts of the |
world they would move the same distance |
in but five years. |
Migratory Magnetic Poles.
Another interesting bit of work in which |
our magneticians will cooperate is the re- |
location of the north magnetic pole and the |
discovery of that to the south. When first |
discovered seventy years ago by Captain |
Ross of the British navy the north mag |
netic poe was at or about Boothia Felix, |
In British North America, above Hudson's |
bay. At this spot the dipping needle stood |
on end, its north extremity pointing down
toward the center of the earth.
Borchgrevink. the antarctic explorer who |
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