rked keenly to make the "wireless" a
success, and the final event was considered to be a public misfortune.
However, the honours were to be retrieved during the following year.
It fell to the lot of most of the Staff that they developed an interest
in terrestrial magnetism. For one thing every man had carried boulders
to the great stockade surrounding the Magnetograph House. Then, too,
recorders were regularly needed to assist the magnetician in the
absolute Hut. There, if the temperature were not too low and the
observations not too lengthy, the recorder stepped out into the blizzard
with the conviction that he had learned something of value, and, when
he sat down to dinner that night, it was with a genial sense of his own
altruism. In his diary he would write it all up for his own edification.
It would be on this wise: The Earth's magnetic force, which is
the active agent in maintaining the compass-needle in the magnetic
meridian** at any particular spot, acts, not as is popularly supposed,
in a horizontal plane, but at a certain angle of inclination with the
Earth's surface. The nearer the magnetic poles the more nearly vertical
does the freely suspended needle become. At the South Magnetic Pole it
assumes a vertical position with the south end downwards; at the North
Magnetic Pole it stands on its other end. At the intermediate positions
near the equator the whole force is exerted, swinging the needle in the
horizontal plane, and in such regions ordinary ships' compasses
pivoted to move freely only in a horizontal plane give the greatest
satisfaction. On approaching the magnetic poles, compasses become
sluggish, for the horizontal deflecting force falls off rapidly. The
force, acting in a vertical direction, tending to make the needle dip,
correspondingly increases, but is of no value for navigation purposes.
However, in the scientific discussion of terrestrial magnetism, both the
horizontal and vertical components as well as the absolute value of the
total force are important, and the determination of these "elements"
is the work of the magnetician. Affecting the average values of the
"magnetic elements" at any one spot on the Earth's surface are regular
diurnal oscillations, apparent only by the application of very delicate
methods of observation: also there are sudden large irregular movements
referred to as magnetic storms; the latter are always specially
noticeable when unusually bright auroral phenomena are
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