Apparatus. Two magnetized sewing-needles (magnetized as in [Exp. 9]); the cork, etc., of [Exp. 10].
27. Directions. (A) Float each little bar magnet (needles) separately to locate the N poles.
(B) Leave one magnet upon the cork, and with the hand bring the N pole of the other magnet immediately over the N pole of the floating one. Note the result.
(C) Try the effect of two S poles upon each other.
(D) What is the result when a N pole of one is brought near a S pole of the other?
EXPERIMENT 12. To study the action of a magnet upon soft iron.
Apparatus. A magnetized sewing-needle; cork, etc., of [Exp. 10]; a piece of soft iron wire, 3 in. long; iron filings.
28. Directions. (A) Test the wire for magnetism with filings. Be sure that it is not magnetized. If it shows any magnetism, twist it thoroughly before using. ([Exp. 19].)
(B) Float the magnetized needle ([Exp. 10]), then bring the end of the wire near one pole of the needle and then near the other pole.
(C) Place the wire upon the cork, hold the needle in the hand and experiment.