Eliza Elizabeth Macarthur-Onslow (1840-1911), property owner, was born on 8 May 1840 at 'Camden Park', Menangle, New South Wales, only child of Emily (born Stone) and James Macarthur, and granddaughter of Elizabeth and John Macarthur. She was educated at home. The family left for England in 1860 and she did the Grand Tour with her parents, returning in 1864 to 'Camden Park', the decision to return being influenced by her wish to live in Australia. On 31 January 1867 at Camden she married Captain Arthur Alexander Walton Onslow, then on sick leave from the navy. (He retired in 1871). They lived at 'Camden Park' and in Sydney. Of their six sons and two daughters, a daughter and a son died in infancy. On James Macarthur's death in 1867, Elizabeth inherited a share in 'Camden Park' and in valuable city land and properties at Taralga and at Sutton Forest. Her relationship with her mother, who lived with her at 'Camden Park' until her death in 1880, was close and affectionate. Elizabeth herself was widowed in 1882. She was in England with her children for much of 1887-91, or travelling on the continent. Her eldest son James graduated from Cambridge BA LLB (1890). Following the deaths of her uncles Edward and William without issue, the remaining Macarthur interests passed to Elizabeth; James was heir to his great- uncle William Sharp Macleay (q.v. Fanny Macleay).
While overseas Elizabeth studied developments in the dairying industry. She installed at 'Camden Park' twelve 'cooperative dairies' and a central creamery, to process cream to butter. Though the term cooperative was used, the operating principle was métayage share-farming: the dairymen's families were housed and supplied with farming equipment; the cows were owned by the Macarthurs and allocated in herds of 60 to each farming family. It was a profitable enterprise. The 'dairies', where cream was separated from milk, were equipped with steam, and the promotion of 'Camden Park' produce strongly featured hygiene. Mrs Onslow added a piggery to the dairy, took advice from the Department of Agriculture on phylloxera-resistant grapes, and experimented in sericulture. She joined both the Women's Cooperative Silk-Growing and Industrial Association and the Victorian Silk Culture Association, planting mulberry cuttings at Camden, intending to use the labour of farmers' daughters on a share basis. This project was not successful.
Elizabeth was a friend of Lucy Osburn (q.v.) and had tried to persuade her to return with her to New South Wales. Though not closely involved in the women's movement, through the silk cooperative she was in contact with some who were. She was a member (with Frances Levvy (q.v.)) of the women's branch of the Society for the Prevention of Cruelty to Animals. Mrs Onslow was a local patron. Camden benefited from her support for the Schools of Arts, the Agricultural Society and Macarthur Park; she donated a set of memorial bells to St John's Church and a clock.
Four of her sons served in the Boer War; her personal intervention with New South Wales Ministers, along with son James's offer to pay for the first 100 horses, is reputed to have decided the government to offer the British a detachment of troops. She contributed generously to the Dreadnought appeal in 1909.
Though displaying in her lifetime a strong attachment to family traditions (she changed her name to Macarthur-Onslow in 1892), the editing of the Macarthur records (Some Early Records of the Macarthurs of Camden), commenced with her father before his death, was left to her daughter to complete. She died on 2 August 1911 while on a visit to England. Her estate was sworn at 196,668 pounds. A shrewd business mind, receptive to advice from her attorney P. G. King, consolidated the Macarthur fortune. In 1899 she converted the 'Camden Park' estate into a company with her children as shareholders.
Heather Radi