of course, elevates the other pole above it ; this is called the inclination or dipping of the magnet. (5.) Any magnet may be made to impart its properties to iron and steel.

1

CONVERSATION XXIV.

Magnetic Attraction and Repulsion.

TUTOR. Having mentioned the seve ral properties of the magnet or loadstone, I intend, at this time, to enter more particularly into the nature of magnetic attraction and repulsion.-Here is a thin iron bar, eight or nine inches long, rendered magnetic, and on that account it is now called an artificial magnet: I bring a small piece of iron within a little distance of one of the poles of the magnet, and you see it is attracted or drawn to it.

Charles. Will not the same effect be produced, if the iron be presented to any other part of the magnet?

Tutor. The attraction is strongest at the poles, and it grows less and less in proportion to the distance of any part from the

poles, so that in the middle, between the poles, there is no attraction, as you shall see by means of this large needle.

James. When you held the needle near the pole of the magnet, the magnet moved to that, which looks as if the needle attracted the magnet.

Tutor. You are right: the attraction is mutual, as is evident from the following experiment. I place this small magnet on a piece of cork, and the needle on another piece, and let them float on water, at a little distance from each other, and you observe that the magnet moves towards the iron, as much as the iron moves towards the magnet.

Charles. If two magnets were put in this situation, what would be produced?

Tutor. If poles of the same name, that is, the two north, or the two south, be brought near together, they will repel one another; but if a north and south pole be presented, the same kind of attaction will be visible, as there was between the magnet and needle.

James. Will there be any attraction or repulsion if other bodies, as paper, or thin slips of wood, be placed between the magnets, or between the magnet and iron?

Tutor. Neither the magnetic attraction 3 nor repulsion is in the least diminished, or in any away affected by the interposition of any kind of bodies, except iron. Bring the magnets together within the attracting or repelling distance, and hold a slip of wood between them: you see they both come to the wood.

Charles. You said that iron was more easily rendered magnetic than steel, does it retain the properties as long too?

Tutor. If a piece of soft iron, and a piece of hard steel, be brought within the influence of a magnet, the iron will be most forcibly attracted, but it will almost instantly lose its acquired magnetism, whereas the hard steel will preserve it along time.

James. Is magnetic attraction and repulsion at all like what we have sometimes seen in electricity?

Tutor. In some instances there is a great similarity: Ex. I tie two pieces of soft wire Plate VIII. Fig. 28.) each to a separate thread which join at top, and let them hang freely from a hook x. If I bring the mark ed or north end of a magnetic bar just under them, you will see the wires repel one another, as they are shown in the figure hanging from z.

Charles. Is that occasioned by the repelling power which both wires have acquired in consequence of being both rendered magnetic with the same pole?

Tutor. It is: and the same thing would have occurred if the south pole had been presented instead of the north.

James. Will they remain long in that position?

Tutor. If the wires are of very soft iron they will quickly lose their magnetic power; but if steel wires be used, as common sewing needles, they will continue to repel each other, after the removal of the magnet.

Ex. II. I lay a sheet of paper flat upon a table, and strew some iron filings upon it.