Lardner’s father was a solicitor in Dublin, who wishes his son to follow the same calling. After some years of uncongenial desk work, Lardner enters Trinity College, Dublin in 1812, obtains a B.A. in 1817 and an M.A. in 1819, winning many prizes. While in Dublin, Lardner begins to write and lecture on scientific and mathematical matters, and to contribute articles for publication by the Irish Academy.
In 1828, Lardner is elected professor of natural philosophy and astronomy at University College, London, a position he holds until he resigns his professorship in 1831. He is the author of numerous mathematical and physical treatises on such subjects as algebraic geometry, differential and integral calculus, and the steam engine. He also writes handbooks on various departments of natural philosophy, but it is as the editor of Lardner’s Cabinet Cyclopædia that he is best remembered.
The Cabinet Cyclopædia eventually comprises 133 volumes with many of the ablest savants of the day contributing to it, including Sir Walter Scott, Thomas Moore, Connop Thirlwall, and Robert Southey. Lardner himself is the author of the treatises on arithmetic, geometry, heat, hydrostatics and pneumatics, mechanics, and electricity. The Cabinet Library and the Museum of Science and Art are his other chief undertakings.
In 1840, Lardner’s career receives a major setback as a result of his involvement with Mary Spicer Heaviside, the wife of Captain Richard Heaviside, of the Dragoon Guards. Lardner runs off to Paris with Mrs. Heaviside and is pursued by her husband. When he catches up with them, Heaviside subjects Lardner to a flogging but is unable to persuade his wife to return with him. Later that year Heaviside successfully sues Lardner for “criminal conversation” (adultery) and receives a judgment of £8,000. The Heavisides are divorced in 1845 and Lardner marries Mary Heaviside in 1846. The scandal effectively ends his career in England, so Lardner and his wife remained in Paris until shortly before his death in 1859. He is able to maintain his career by lecturing in the United States between 1841 and 1844, which proves financially rewarding.