BARLOW, PETER, an able writer on pure and applied mathematics, was born at Norwich in 1776, and died in 18G2. He received a very ordinary education, but improved himself by his own exertions. In 1806 he was appointed mathematical master in the Woolwich Academy, and filled t'iat post for forty-one years. In 1823 he was made a Fellow of the Royal Society, and two years later received the Copley medal. He received many distinctions from British and foreign scientific societies. Mr Barlow's principal works are - Elementary Investigation of the Theory of Numbers, 1811 ; New Mathematical and Philosophical Dictionary, 1814; Essay on Magnetic Attractions, 1820. The investigations on magnetism led to the important practical discovery of a means of rectifying or compensating compass errors in ships. Besides compiling numerous useful tables, Mr Barlow contributed largely to the Encyclopcedia Metropolitans. The most important of his articles are" Theory of Numbers," " Mechanics," "Hydrodynamics," " Pneumatics," " Optics," " Astronomy," " Magnetism," and "Electro-Magnetism," along with the huge volume on " Manufactures."