Magic Square is a square divided into a number of smaller squares or cells, all equal, and each containing one of a series of numbers. These numbers are so placed that the sum of those in each row, column, or diagonal is the same. If the numbers from 1 to 16 are arranged in the following rows, 1, 15, 14,4; 12, 6, 7, 9; 8, 10,11,5; 13, 3, 2,16; they will form a magic square, the sum of the numbers in any row, etc., being 34. From very early times mathematicians amused themselves by constructing these squares. They are supposed to have been introduced into Europe about the 15th century, but to have been known in India from the earliest times. Astrologers invested them with mystical meaning; a square containing only one cell with the number 1 represented the unity of the deity, squares containing 3, 4, 5, 6, 7, or 8 cells in a row were associated with Saturn, Jupiter, Mars, the sun, Venus and Mercury, the planets of the old astrologers. The squares, engraved on stone or metal, were used as talismans or charms to protect the wearer against evil, and are still to be found in India. The theory of the formation of such squares has been chiefly worked out by French mathematicians.