Mallet, Robert (DNB00)

MALLET, ROBERT (1810–1881), civil engineer and scientific investigator, son of John Mallet of Devonshire, who settled in Dublin as an iron, brass, and copper founder, was born in Dublin 3 June 1810. He entered Trinity College in December 1826, graduated B.A. 1830, and M.A. and master in engineering 1862. In 1831 he became a partner in his father’s works, assuming the charge of the Victoria foundry, and expanding it into a large concern, which ultimately absorbed all the engineering works of note in Ireland. One of his first undertakings was raising and sustaining the roof of St. George’s Church, Dublin, a massive construction weighing 133 tons; for this work he was in 1841 awarded the Walker premium by the Institution of Civil Engineers. For Guinness & Co., the brewers, he bored an artesian well, besides constructing steam barrel-washing machines and large sky coolers. In 1836 he built a number of swivel bridges over the Shannon. In May 1839 he was elected as associate of the Institution of Civil Engineers, and was made a member in 1842. He next turned his attention to the supply of water to Dublin, and surveyed the river Dodder in 1841 at his own expense, with a view to furnishing a supply of pure water, and of procuring water for the paper-mills in summer-time. Between 1845 and 1848 he erected many terminal railway stations, engine sheds, and workshops, besides the Nore viaduct, a bridge 200 feet in span, with girders of 22 feet in depth. The Fastnet Rock lighthouse was built by him in 1848–9. His name is well known by his invention of the buckled plate, which he patented in 1852. These plates form the best flooring ever made, combining the maximum of strength with the minimum of depth and weight; with them Westminster and other bridges were floored. In 1854, in view of the Crimean war, he made two monster mortars for throwing 36-inch shells, but they were not used owing to the arrangement of peace with Russia in 1856. On 1 June 1854 he was elected a fellow of the Royal Society.

With the completion of the trunk railway lines in Ireland foundry-work became scarce, and giving up his establishment in Dublin, Mallet in 1861 removed to London and established himself as a consulting engineer. He edited the ‘Practical Mechanic's Journal,’ 1865–9, 4 vols., contributed largely to the ‘Engineer,’ and gave evidence as a scientific witness in patent cases. In 1863 he reported on the Hibernia and other collieries in Westphalia, in 1864 he was interested in the Dublin trunk connecting railway, an unfortunate scheme, and later on he investigated the use of the Thames Tunnel by the East London railway, and the probability of injury to the Royal Observatory at Greenwich. The ‘Catalogue of Scientific Papers’ contains the titles of seventy-four of his papers. He wrote on the action of water on iron, on alloys of copper with tin and zinc, on atmospheric railways, on the application of water power, on fouling of iron ships, on earthquakes, and volcanoes. The Telford medal and premium of the Institution of Civil Engineers was awarded him in 1859, the Cunningham medal of the Royal Irish Academy in 1862, and the Wollaston gold medal of the Geological Society in 1877. He died at Enmore, The Grove, Clapham Road, Surrey, on 5 Nov. 1881.

Besides contributions to the ‘Philosophical Transactions,’ the ‘Minutes of the Proceedings of the Institution of Civil Engineers,’ and other societies, Mallet printed: 1. ‘On the Physical Conditions involved in the Construction of Artillery, with an Investigation of the Value of the Materials employed, and of some Causes of Destruction of Cannon in Service,’ Dublin, 1856. 2. ‘Great Neapolitan Earthquake of 1857,’ 2 vols. 1862. 3. ‘The Practical Mechanic's Journal, Records of the Great Exhibition,’ 1862, 13 pts. 4. ‘The Safes' Challenge Contest at the International Exhibition of Paris in 1867; Statements (with R. F. Fairlie),’ 1868. He edited or translated: 5. ‘Civil Engineering,’ by H. Law, 1869. 6. ‘The Rudiments of Colours and of Colouring,’ by G. Field, 1870. 7. ‘A Practical Manual of Chemical Analysis and Assaying,’ by L. L. de Koninck, 1872; another edition, 1873. 8. ‘The Eruption of Vesuvius in 1872,’ by L. Palmieri, 1873.

[Minutes of Proceedings of Institution of Civil Engineers, 1882, lxviii. 297–304; Proceedings of Roy. Soc. 1882, xxxiii. pp. xix–xx; Quarterly Journal of Geological Soc. 1882, xxxviii. 54–6; Engineer, 11, 18, and 25 Nov. 1881; information from R. T. Mallet, esq., St. Leonards-on-Sea.]

G. C. B.