69. Directions. (A) Place the two bar magnets side by side, so that their unlike poles shall be arranged as in [Fig. 19].
(B) Make the magnetic figure.
70. Directions. (A) Turn one B M end for end, so that their like poles shall be near each other, but otherwise arranged as in [Fig. 19].
(B) Make and study the magnetic figure.
EXPERIMENTS 38–39. To study the lifting power of combinations of bar magnets.
Apparatus for Exps. 38–39. Two bar magnets, B M (No. 21, 22), of about equal strength; iron filings, I F.
71. Directions. (A) Find out about how many filings you can lift with the N pole of one magnet.
(B) Place the two magnets together ([Fig. 20]), their like poles being in contact; then see whether the two N poles will lift more or less filings than one pole.