Cumming, Alexander (1731/21814), watchmaker and mechanician, is said by most sources to have been born in Edinburgh, although there is no trace of his baptism in the parish registers. However, according to the first Scottish Statistical Account (vol. 21, 1799), discovered by Mary Cosh, he was a son of James Cumming of the parish of Duthil, Inverness-shire, for which no registers survive for the relevant period. A precocious mechanical skill apparently brought Cumming to the attention of Lord Milton, who took him into his service. According to some authorities he was apprenticed to a watchmaker in Edinburgh, but supporting evidence is lacking. However, he did become a member of the Philosophical Society of Edinburgh. By 1752 he was working in Inveraray, Argyll, as a watchmaker and enrolled as a burgess. Lord Milton was chief Scottish political agent to Archibald Campbell, third duke of Argyll, and he probably recommended Cumming to his patron, since by 1757 Alexander and his brother John were employed by the duke in making an organ for his new castle at Inveraray. Alexander also made a long-case clock for the castle. The duke of Argyll was the uncle of John Stuart, third earl of Bute, tutor and later prime minister to George III. After Argyll's death in 1761 Cumming probably applied to Bute for patronage, for by 1763 he was established in New Bond Street, London, and had acquired a sufficient reputation to be appointed a member of the commission set up in that year to adjudicate on John Harrison's timekeeper for discovering the longitude at sea, the name then given to what was to prove the first successful marine chronometer. Cumming was one of those who insisted that a second timekeeper must be made according to Harrison's principles in order to prove both that he had fully disclosed his methods, as required by the act of parliament that created the commission, and that he had invented a reliable means of checking longitude. Cumming's Elements of Clock and Watch Work Adapted to Practice (1766), seems to have stemmed partly from an essay he wrote when appointed to the commission on Harrison's timekeeper. He deposited the essay, in which he outlined his ideas about clockwork, with the Philosophical Society of Edinburgh in order to protect himself against the possibility of charges of plagiarism after he had heard Harrison's explanation. The book included one of the earliest designs for a gravity escapement.
Cumming made clocks and watches for a number of eminent contemporaries, including two gold stopwatches for Sir William Hamilton at Naples and in 1769 a watch for Dr Charles Blagden, for whom he also ordered an electrifying machine from the instrument maker Jesse Ramsden. It was at this stage in his career that Cumming married Elizabeth Oswald (c.17441815) at St Anne's, Soho, London, on 13 May 1769. There were four children of the marriage, including a son, , who became a senior official at the India Office, and a daughter, Ann.
Cumming was especially interested in the measurement of air pressure and became involved in developing the ideas first outlined by Robert Hooke for recording barometer readings. In 1765 he made a special clock for George III that recorded on a chart the variations in barometer readings over the course of a year, and was paid £150 annually to maintain it. This is usually claimed to be the first effective recording barograph. In the following year Cumming made a slightly altered version of the barograph clock for his own use. After his death it was bought by Luke Howard, who used it for the observations that formed the basis of his pioneering work The Climate of London (1820). It is now preserved at the Science Museum, London. Between 1770 and 1773 Cumming made experiments designed to investigate the effects of changes in temperature on the barometer and to examine its use for determining height above sea level. Some of these investigations were carried out at Luton Hoo Park, the home of the third earl of Bute, a fellow Scot, who took up an interest in botany and other scientific matters when he retired from politics.
While his principal occupation was making clocks and watches, Cumming also developed a number of mechanical devices. According to J. Hill in The Construction of Timber from its Early Growth (1770), Cumming invented the microtome, a device for cutting very thin samples for examination under a microscope, an example of which is preserved in the George III collection at the Science Museum. The first example of this device was made for Bute, and several were among the effects sold after the earl's death in 1792. In 1781 Cumming's achievements were recognized when he was made an honorary freeman of the Clockmakers' Company of the City of London, and he was elected a fellow of the Royal Society of Edinburgh in 1783. In that year, on the orders of the king, he was involved in experiments at Windsor on a new hydraulic machine for raising water. Again, the first trials of the machine had been carried out at Bute's estate near Luton.
In the early 1790s Cumming retired to Penton Place in Pentonville, then a suburb of London, where he wrote a number of essays on mechanical questions. These included Observations on the effects which carriage wheels, with rims of different shapes, have on the roads (London, 1797) and A Dissertation on the Influence of Gravitation Considered as a Mechanic Power (Edinburgh, 1803). In 1779 he had invested in land leased from Henry Penton MP and, with his brother John, contributed significantly to the development of the district, and became a magistrate. He was asked to act as an arbitrator in a dispute in 1812 over the price of a clock made by William Hardie for the Royal Greenwich Observatory. Cumming died at Penton Place on 8 March 1814, aged eighty-two, and was buried on 15 March at St James's Chapel, Pentonville Road, Finsbury, London, an offshoot that he had helped to found of the parish of St James's, Clerkenwell.
In an obituary in the Gentleman's Magazine Cumming was described as eminent for his genius and knowledge in the mechanical sciences. Other commentators, both among his contemporaries and later, while acknowledging his talents, have been more critical. William Ludlam challenged some of the interpretations of mechanical theory given in The Elements of Clock and Watch Work in a letter to the Gentleman's Magazine (1st ser., 57, 1787, 30002), and in the mid-twentieth century G. H. Baillie commented of the same work that the reasoning throughout is turgid and frequently wrong (p. 270). Also, Cumming failed to appreciate the significance of some of the improvements Harrison had incorporated in his marine timekeeper. However, criticisms of Cumming's theoretical knowledge do not detract from the excellence of many of his timepieces and his contributions to scientific enquiry and mechanical invention.
F. J. Britten, Old clocks and watches and their makers, ed. G. H. Baillie, C. Ilbert, and C. Clutton, 9th edn (1982) · G. H. Baillie, Clocks and watches: an historical bibliography (1951) · [J. Watkins and F. Shoberl], A biographical dictionary of the living authors of Great Britain and Ireland (1816) · Watt, Bibl. Brit. · H. A. Lloyd, Horology and meteorology, NMM, Foulkes MSS · parish register (marriage), St Anne, Soho, London, 1769 · parish register (burial), St James, Pentonville Road, Finsbury, London, 15 March 1814 · J. Hill, The construction of timber from its early growth (1770) · Antiques Trade Gazette (13 March 1982) · A. Q. Morton and J. A. Wess, Public and private science: the King George III collection (1993) · W. J. H. Andrewes, Even Newton could be wrong: the story of Harrison's first three sea clocks, The quest for longitude, ed. W. J. H. Andrewes (1996), 189234 · GM, 1st ser., 84/1 (1814), 414 · M. Cosh, Clockmaker extraordinary: the career of Alexander Cumming, Country Life (12 June 1969), 152835
GL, Clockmakers' Company MSS, 3964, 3973
S. Drummond, oils, Guildhall, London, Clockmakers' Company Museum
Wealth at death
under £1000: TNA: PRO, death duty registers, IR 26/199