In the Museum of the Royal Society are two curiosities of the
seventeenth century which are objects of much interest in association
with the electric discoveries of our day. These are a Clock, described
by the Count Malagatti (who accompanied Cosmo III., Grand Duke of
Tuscany, to inspect the Museum in 1669) as more worthy of observation
than all the other objects in the cabinet. Its “movements are derived
from the vicinity of a loadstone, and it is so adjusted as to discover
the distance of countries at sea by the longitude.” The analogy
between this clock and the electric clock of the present day is very
remarkable. Of kindred interest is “Hook’s Magnetic Watch,” often
alluded to in the Royal Society’s Journal-book of 1669 as “going slower
or faster according to the greater or less distance of the loadstone,
and so moving regularly in any posture.”