John Skirrow, British civil engineer and architect, was sent to the Cape Colony by the British Admiralty in 1825 as clerk-of-works to supervise the building of the Royal Observatory, Cape of Good Hope. He arrived unannounced in Table Bay on 22 February, to the pleasant surprise of His Majesty's Astronomer at the Cape, Reverend Fearon Fallows*, who handed responsibility for the construction over to him. Skirrow immediately realised that the existing specifications for the building were inadequate and renegotiated the building contract. Among others he provided clear specifications relating to the quality of mortar and building stone, and the methods of construction to be used. He also introduced the practice of allowing the wooden roofbeams freedom of play (by resting their ends on plates protruding from the walls) so that their expansion or contraction would not place stress on the structure. His work at the Royal Observatory had a lasting effect on building practices at the Cape, particularly on the standard of masonry work.
Initially Skirrow lived in a cottage on the grounds of the observatory but late in 1827 he moved to Cape Town and started taking on other work. As a result progress at the observatory, particularly the completion of the instrument piers, slowed dramatically. Eventually a function to celebrate the laying of the last stone of the mural circle pier was held on 29 October 1828. Among the guests were Skirrow, Fallows, M.J. Johnson*, Captain W. Ronald*, the governor (Sir Lowry Cole) and the colonial secretary (John Bell). The two rotatable domes arrived from England only in September 1829, when Skirrow supervised their installation. Owing to the high standards he set the building remains complete. It was the first neo-classical building in South Africa and is still probably the finest local example of this architectural style.
As early as 1826 the acting governor, Sir Richard Bourke, recommended to the secretary to the colonies in England that Skirrow be appointed as government architect and civil engineer on the basis of the high quality of his work at the observatory. He was officially appointed as government architect and superintendent of the Cape Town water works, in the office of the surveyor-general, C.C. Michel*, towards the end of 1828. Soon thereafter he was also assistant civil engineer to the government, holding these positions to 1834. From 1838 to 1840 he served as government civil engineer, while he still (or again) functioned as government architect in 1845. In between his official duties he developed an extensive private practice as a land surveyor, architect and building contractor. Among others he supervised, or jointly supervised, the building of St George's Church (later St George's Cathedral), St John's Church in Wynberg, and private homes. In 1842 he designed and supervised the building of a wooden bridge across the Liesbeek River between the Royal Observatory and Cape Town. He resided in Cape Town for his whole career and was regarded as competent and careful in his work and a man of integrity. He was still listed as a sworn land surveyor in the Cape of Good Hope almanac for 1846, the year of his death.
Skirrow appears to have been interested in natural history, for during 1825-1826 he presented 20 birds and a few reptiles to Dr Andrew Smith*, curator of the newly established South African Museum. He was a member of the South African Literary and Scientific Institution from 1832, the year of its formation, and served on its council from about 1839 to his death. In 1827 he was a member of the newly founded Cape of Good Hope Horticultural Society. He was not married, was a Freemason, and had an interest in astronomy. During 1843 he stayed at the Royal Observatory for a few days to assist C.P. Smyth* with observations of the Great Comet of 1843.