small
observatory at Berlin, whose more immediate object was to institute a
series of simultaneous observations at concerted hours at Berlin, Paris,
and Freiburg. In 1829 magnetic stations were established throughout
Northern Asia, in connection with an expedition to that country which
emanated from the Russian government; and in 1832 M. Gauss, the
illustrious founder of a general theory of terrestrial magnetism,
established a magnetic observatory at Goettingen, which was completed in
1834, and furnished with his ingenious instruments.

In 1836 Baron Humboldt addressed a long and highly-interesting letter to
the Duke of Sussex, then president of the Royal Society, urging the
establishment of regular magnetical stations in the British possessions in
North America, Australia, the Cape of Good Hope, and between the tropics,
not only for the observation of the momentary perturbations of the needle,
but also for that of its periodical and secular movements. This appeal was
nobly responded to.

The Royal Society, in conjunction with the British Association, called on
government to advance the necessary funds to establish magnetical
observatories at Greenwich, and in various parts of the British
possessions; and in 1839-40 magnetical establishments were in activity at
St. Helena, the Cape of Good Hope, Canada, and Van Diemen's Land. The
munificence of the directors of the East India Company founded and
furnished, at the request of the Royal Society, magnetic observatories at
Simla, Madras, Bombay, and Singapore, and the observations will be
published in a similar form to those of the British observatories. We will
now briefly describe the scheme of observations, and the manner of making
them in the different observatories.

Each observatory is supplied with three magnetometers, or bars of
magnetized steel, delicately suspended by threads of raw silk, which
measure the magnetical declination, horizontal intensity, and vertical
force--and such astronomical apparatus as is required for ascertaining the
time and the true meridian. To these have also been added in each case a
most complete and perfect set of meteorological instruments, carefully
compared with the standards in possession of the Royal Society, not only
for the purpose of affording the necessary corrections of the magnetic
observations, but also with a view to obtaining at each station, at very
little additional cost and trouble, a complete series of meteorological