National High Magnetic Field Laboratory
Magnet Academy: Magnetometer 1832
The Earth, the moon, the stars and just about everything in between has a magnetic field, and scientists use magnetometers when they need to know the strength of those fields.
National High Magnetic Field Laboratory
Magnet Academy: Bell Telephone 1876
Acoustics, variable resistance and allegations of foul play contribute to the exciting story of the invention of the telephone.
National High Magnetic Field Laboratory
Magnet Academy: Seeing Magnetic Field Lines
Compasses and special metal filings help you "see" the invisible force of magnetic fields. [2:25]