e of a
magnetic needle, suspended on a pivot, or to a light body swimming on
the surface of the water, (in which you have placed a magnetic bar,)
that body will approach the wand, and present that end which contains
the south end of the bar: but if you present the north or south end of
the wand to the north or south end of the needle, it will recede from
it.

[E] For the more clearly explaining this, it is to be
observed, that the two ends of a magnet are called its poles.
When placed on a pivot, in just equilibrium, that end which
turns to the north is called the north pole, and the other
end the south pole.

_The Mysterious Watch._

You desire any person to lend you his watch, and ask him if it will go
when laid on the table. He will, no doubt, say it will; in which case,
you place it over the end of the magnet, and it will presently stop.
You then mark the precise spot where you placed the watch, and, moving
the point of the magnet, you give the watch to another person, and
desire him to make the experiment; in which he not succeeding, you
give it to a third (at the same time replacing the magnet) and he will
immediately perform it.

This experiment cannot be effected, unless you use a very strongly
impregnated magnetic bar, (which may be purchased at the opticians',)
and the balance of the watch must be of steel, which may be easily
ascertained by previously opening it, and looking at the works.

_The Magnetic Dial._

Procure a circle of wood or ivory, about 5 or 6 inches diameter, which
must turn quite free on a stand with a circular border; on the ivory
or wood circle fix a pasteboard, on which you place, in proper
divisions, the hours, as on a dial. There must be a small groove in
the circular frame, to receive the pasteboard circle; and observe,
that the dial must be made to turn so free, that it may go round
without moving the circular border in which it is placed.

Between the pasteboard circle and the bottom of the frame, place a
small artificial magnet, that has a hole in its middle. On the outside
of the frame, place a small pin, which serves to show when the
magnetic needle is to stop. This needle must turn quite free on its
pivot, and its two sides should be in exact equilibrium.

Then provide a small bag, with five or six divisions, like a lady's
work-bag, but smaller. In one of these divisions put small square
pieces of pasteboard, on which are written the numbers from