In this arrangement he found that
additional heat carried up the mercury in the jar, as much as it
carried down the jar by the elongation of the rod. Consequently, the
motion of the one perfectly compensated the motion of the other, and
the effective centre of the weight always remained at the same precise
distance from the top of the rod. By the application of this
compensating pendulum, clocks are now constructed that do not vary to
the extent of a tenth of a second in a day.

Soon after the invention of Graham's mercurial pendulum, John
Harrison--the same clever mechanician who received L.20,000 from
government for making a chronometer that went to Jamaica in one year
and returned in another with an accumulated error of only 1 minute and
54 seconds--hit upon another means of gaining the same end. He brought
a steel rod down from the point of suspension, turned it up into a
copper rod of less length; and from the top of this hung the weight.
He fixed the lengths of the steel and copper rods, which expand
unequally, in such a way that the steel carried the copper down
exactly as much as the copper carried the weight up; and thus the
centre of the weight was still kept at the same distance from the real
point of suspension. Harrison's pendulum is generally seen in somewhat
the form of a gridiron, because many parallel bars of copper and steel
are used in its construction, for the sake of rendering it firm and
unyielding in all its parts.

MAGIC IN INDIA.

A correspondent in India tells us that a military friend of his, on
returning to England, and finding all astir there about mesmerism,
writes to him that he had often had much cause to regret that, during
his long residence of more than twenty-eight years in India, he was
ignorant of the very name or existence of mesmerism; as he could
recall to mind many instances of what he then deemed to be native
superstitions, on which he now looked very differently, believing them
to be the direct effects of mesmeric influence. These instances are
daily and hourly exhibited in Indian dwellings, though either passing
without notice, or ascribed to other causes. Children in India,
especially European children, seldom go to sleep without being
subjected to some such influence, either by the ayahs or the attendant
bearers; and our military friend says, that he has himself repeatedly,
in a few seconds, been the means of tranquillising a fractious,
teething child, and thro