In March, 1886, many years of prospecting culminated in a rich gold strike on the farm Langlaagte, in that part of the Transvaal now known as the Witwatersrand. This farm is now part of the city of Johannesburg (see Plate 1). The gold was discovered in a conglomerate bed, later to be known as the Main Reef. As this conglomerate was traced along its outcrop, it was quickly realised that a new and important goldfield had been discovered. That this view was justified is evident from Plate l, which shows all the areas held under mining lease today in the Transvaal and Orange Free State, totalling some 700 sq. miles.