Dionysius Lardner

Career in London

In 1828, Lardner was elected professor of natural philosophy and astronomy at University College, London, a position he held until he resigned his professorship in 1831.

Lardner showed himself to be a successful populariser of science, giving talks on contemporary topics such as Babbage's Difference Engine (1834). He was the author of numerous mathematical and physical treatises on such subjects as algebraic geometry (1823), the differential and integral calculus (1825), and the steam engine (1828). He also wrote hand-books on various departments of natural philosophy (1854–1856); but it is as the editor of Lardner's Cabinet Cyclopædia (1830–1844) that he is best remembered.

The Cabinet Cyclopædia eventually comprised 133 volumes, and many of the ablest savants of the day contributed to it. Sir Walter Scott contributed a history of Scotland and Thomas Moore contributed a history of Ireland. Connop Thirlwall provided a history of Ancient Greece, whilst Robert Southey provided a section on naval history. Many eminent scientists contributed as well. Lardner himself was the author of the treatises on arithmetic, geometry, heat, hydrostatics and pneumatics, mechanics (in conjunction with Henry Kater) and electricity (in conjunction with C.V. Walker).

The Cabinet Library (9 vols., 1830–1832), the Edinburgh Cabinet Library (38 vols., 1830–1844) and the Museum of Science and Art (12 vols., 1854–1856) were his other chief undertakings. A few original papers appear in the Royal Irish Academy's Transactions (1824), in the Royal Society's Proceedings (1831–1836) and in the Astronomical Society's Monthly Notices (1852–1853); and two Reports to the British Association on railway constants (1838, 1841) are from his pen.

Involvement in scandal

In 1840 Lardner's career received a major setback as a result of his involvement with Mary Spicer Heaviside, the wife of Captain Richard Heaviside, of the Dragoon Guards. He had previously been married to Cecilia Flood from 1815 to their separation in 1820. Lardner ran off to Paris with Mrs Heaviside, pursued by her husband. When he caught up with them, Heaviside subjected Lardner to a flogging but he was unable to persuade his wife to return with him. Later that year he successfully sued Lardner for "criminal conversation" (adultery) and received a judgment of £8,000.

The Heavisides were divorced in 1845, and in 1846 Lardner was able to marry Mary Heaviside. The scandal caused by his affair with a married woman effectively ended his career in England, so Lardner and his wife remained in Paris until shortly before his death in 1859. He was able to maintain his career by lecturing in the United States between 1841 and 1844, which proved financially rewarding, realising £40,000.

He died in Naples, Italy, and is buried in the Cimitero degli Inglesi there.

Disagreements with Brunel

Lardner became involved in a number of ill-advised public disagreements with Isambard Kingdom Brunel regarding technical matters, in which he came off the worse.

During the 1833 Parliamentary hearings discussing the proposal of the Great Western Railway, Lardner criticised Brunel's design of the Box Tunnel. The tunnel had a 1-in-100 gradient from the east end to the west end. Lardner asserted that if a train's brakes were to fail in the tunnel, it would accelerate to over 120 mph (190 km/h), at which speed the train would break up and kill the passengers. Brunel pointed out that Lardner's calculations totally disregarded air resistance and friction, a basic error.

In 1836, when Brunel was proposing to build SS Great Western for the 3,500 mi (5,600 km) transatlantic passage to New York, at a meeting of the British Association for the Advancement of Science, Lardner stated that:

As the project of making the voyage directly from New York to Liverpool, it was perfectly chimerical, and they might as well talk of making the voyage from New York to the moon... 2,080 mi (3,350 km) is the longest run that a steamer could encounter – at the end of that distance she would require a relay of coals.

Again, Brunel was able to show that Lardner's calculations were too simplistic. The principle that Brunel understood, which Lardner did not, was that the carrying capacity of a ship increases as the cube of its dimensions, whilst the water resistance only increases as the square of its dimensions. This meant that large ships were more fuel efficient, and could carry sufficient coal for the long voyage across the Atlantic. Brunel was proved right when the Great Western steamed into New York harbour with 200 long tons (200 tonnes) of coal to spare.

In 1838 while Brunel was building the broad-gauge Great Western Railway, Lardner carried out some experiments with the company's flagship locomotive, North Star. He asserted that, whilst the engine was capable of hauling 82 long tons (83 tonnes) at 33 mph (53 km/h), it was only capable of hauling 16 long tons (16 tonnes) at 41 mph (66 km/h). He also recorded excessive fuel consumption at higher speeds. Lardner attributed this to the greater wind resistance of broad-gauge engines. Brunel and his assistant Daniel Gooch carried out their own experiments on the same locomotive and found that the only problem was that the blast pipe was too small. This was easily rectified and the North Star's performance immediately improved. At the next meeting of the company's directors, Brunel triumphantly dismissed Lardner's evidence.

Contemporary influence

Lardner is mentioned in Karl Marx's Das Kapital and was well respected as an economist. He mixed with the rich and famous. He was involved in the founding of the University of London and was the first person to hold the post of Professor of Natural Philosophy and Astronomy there. He was influential in publicising Charles Babbage's Difference Engine.

Whilst lecturing in America Lardner was paid by Norris Brothers, the largest firm of locomotive builders, to investigate a fatal accident in Reading, near Philadelphia, where a boiler had exploded on a newly made train. Lardner pronounced that the accident had been caused by lightning, which meant that Norris Brothers were not personally liable for the accident. A committee of the Franklin Institute pointed out that there was no lightning present at that time and that the pumps had been faulty, the water indicator was ill-designed and the bridge bands made of cast iron rather than wrought iron. The Coroner's inquest jury were persuaded by Lardner that the accident was an 'act of God' but the company were careful to design their later locomotives with wrought-iron bands.