The exact power of magnets can be measured by a gauss-meter which is a costly instrument. Hence the power of a magnet is generally estimated by its capacity to lift iron weight. The more weight a magnet can lift, the more powerful it is considered to be. A child’s horse-shoe magnet sold as a toy (which can relieve toothache) is about 300 gauss. The author uses magnets of upto 3000 gauss power to treat chronic diseases.
It is said that first of all bar magnets were made. As the poles of a bar magnets are at the extreme ends of the magnet, which are distantly and oppositely placed, the power of the magnet is not very strong. Then U-shape or Horse-shoe magnets were designed so that both the poles may be close to each other. Such magnets are more powerful and can lift more iron-weight.
But there is a gap or open space between the two poles of such magnets. In order to improve upon these magnets also, ring magnets or solid cylindrical magnets were made, so that there is no such gap between the two poles. Such magnets are still more powerful and can lift heavier weights.