James Ferguson, a Scottish experimental philosopher and astronomer, born near Keith, Banffshire, in 1710, died in London, Nov. 16, 1776. His father, a day laborer, taught him to read and write, which was the only education he was able to bestow on his children. When seven or eight years of age his attention was attracted to mechanics by observing his father raise a heavy weight with a lever. He investigated the principle and made several machines combining the lever and the pulley, which he described in a treatise with drawings. On showing this to a gentleman, he was surprised to find that those things had been treated of before, but was equally pleased that he had discovered the true principle. While tending sheep he made models of mills, spinning wheels, and other machines, acquired the rudiments of astronomy, taught himself to draw, made maps, and learned the principles of geography. By the aid of patrons he afterward studied portrait painting in Edinburgh, and next medicine, but finally devoted himself to astronomy. In 1743 he removed to London, where he attracted attention by a publication of astronomical tables. In 1747 he published A Dissertation on the Phenomena of the Harvest Moon," and afterward lectured in many places on experimental philosophy and astronomy.

George III. settled on him a pension of £50. His latter years were mostly devoted to the delivery of his lectures, which had become very popular. The most important of his works are: "Astronomy Explained on Sir Isaac Newton's Principles (4to, London, 1750);Lectures on Mechanics," etc. (8vo, 1764); An Easy Introduction to Astronomy (1769);An Introduction to Electricity" (1770); and "Art of Drawing in Perspective" (1775). Sir David Brewster published corrected editions of his "Lectures" and "Astronomy in 1805 and 1811.