interested in New Zealand. In 1840 there were crop failures in the other Australian colonies, upon which Adelaide still relied for food, and the cost of living increased rapidly. Gawler increased public expenditure to prevent an economic collapse, which resulted in bankruptcy and later, changes to the way the colony was run (see South Australia Act, 1842). Over £200,000 in bills had been amassed and the land fund in London had been exhausted. The British Parliament approved a £155,000 loan (later made a gift) to bail-out the colony. A head had to roll and Captain George Grey was sent to replace Gawler. Despite having been recalled, Governor Gawler had put Adelaide on a firm footing, making South Australia agriculturally self-sufficient, building infrastructure such as the Adelaide Gaol, and restoring public confidence. Grey Grey, 29 at the time, issued the news of Gawler's recall himself, from the steps of government house on 15 May 1841. He slashed public expenditure, turning public opinion against him (which Grey ignored). Silver was discovered at Glen Osmond the same year, which lifted spirits and spurred on discoveries of other finds in the Mount Lofty Ranges. Copper was discovered near Kapunda in 1842. In 1845 even larger deposits of copper were discovered at Burra which brought wealth to the Adelaide shopkeepers who invested in the mine. With a series of good harvests and expanding agriculture, Adelaide exported meat, wool, wine, fruit and wheat. John Ridley invented a reaping machine in 1843 which changed farming methods throughout South Australia and the nation at large. By 1843, of land was growing wheat (contrasted with in 1838). Toward the end of the century South Australia became known as the "granary of Australia". From a low point in 1842 when 642 out of 1,915 houses were abandoned and there was talk of abandoning the settlement, Adelaide was a bustling city when Grey left to govern New Zealand in 1845. 1850–1900 Gold discoveries in Victoria in 1851 brought a severe labour shortage due to the exodus of workers leaving to seek their fortunes on the goldfields. However, this also led to a high demand for South Australian wheat. The situation improved when prospectors returned with their gold finds. South Australians were keen to establish trade links with Victoria and New South Wales, however overland transport was too slow. A£4,000 prize was offered in 1850 by the South Australian government for the