observations. In order that the observations may be made at the same
periods of time, it was resolved that the mean time at Goettingen should be
employed at all the stations, without any regard to the apparent times of
day at the stations themselves. Each day is supposed to be divided into
twelve equal portions of two hours each, commencing at all the stations at
the same instants of absolute time, which are called the magnetic hours.
At the commencement of each period of two hours throughout the day and
night, with the exception of Sundays, the magnetometers are observed, and
the meteorological instruments read off. Independently of these
observations, others are made at stated periodical intervals every two
minutes and a half during twenty-four hours. These are known by the name
of "turn-day observations." Printed forms for registering the observations
have been prepared with great care, in order that a complete form of
registry may be preserved--a point of great importance, when it is
remembered that all the observations made at the different stations must
eventually be reduced and analyzed. A singularly felicitous adaptation of
photography has been carried into effect with the magnetometers. By means
of mirrors attached to their arms, reflected light is cast on
highly-sensitive photographic paper wound round a cylinder moved by
clockwork, and the slightest variation of the magnets is registered with
the greatest accuracy.

The period has not yet arrived for reaping the fruits of all the labor
carried on in the magnetic observatories at home and abroad, but already
certain results have been deduced from the observations which are highly
interesting. It appears that if the globe be divided into an eastern and a
western hemisphere by a plane coinciding with the meridians of 100 deg. and
280 deg., the western hemisphere, or that comprising the Americas and the
Pacific Ocean, has a much higher magnetic intensity distributed generally
over its surface than the eastern hemisphere, containing Europe and
Africa, and the adjacent part of the Atlantic Ocean. The distribution of
the magnetic intensity in the intertropical regions of the globe affords
evidence of two governing magnetic centres in each hemisphere. The highest
magnetic intensity which has been observed is more than twice as great as
the lowest. It had long been known that in Europe the north end of a
magnet suspended horizontally (meaning by the north end that whic