The next important event in the history of the Transvaal was the exploitation of its gold mines. Gold was discovered there soon after the opening of the diamond mines, but not under very promising conditions. It exists in a conglomerate rock, whose beds extend over an area of seventy by forty miles, and through a depth of from two to twenty feet; but years passed before the richness in metal of these rocks was discovered, and it was not until after the Boer war that mining fairly began. No one in his wildest dreams foresaw that these "banket" beds would in time yield gold to the value of more than $60,000,000 a year. The yield of the diamond mines was also enormous, and these two incitements brought a steady stream of new settlers to that region, destined before many years greatly to outnumber the sturdy farmers and herders of Dutch descent. [=The Career of Cecil Rhodes=] In the vicinity of the gold mines, not far from Pretoria, the Boer capital, rose the mining city of Johannesburg, which now has a population of more than 100,000 souls, of whom half are European miners and nearly all the remainder are natives. The great event in the history of the diamond mines was the advent thither of Cecil Rhodes. This remarkable man, the son of a country parson in England, who was ordered to South Africa for the benefit of his failing lungs, displayed such enterprise and ability that he soon became the leading figure in the diamond mining industry, organizing a company that controlled the mines, and accumulating an immense fortune. This accomplished, he entered actively into South African politics, and was not long in immensely extending the dominion of Great Britain in that region of the earth. He obtained from Lord Salisbury, prime minister of Great Britain, a royal charter giving him the right to occupy and govern the great territory lying between the Limpopo River on the south and the Zambesi on the north, and extending far to the north and the west of the South African Republic. With an expedition of a thousand men, volunteers from the Transvaal and the Cape Colony, Rhodes marched north through a country filled with armed Zulus,--the best fighting stuff in Africa,--and reached the spot where now stands the flourishing town of Fort Salisbury without firing a shot or losing a man. Here gold mines were opened, the resources of the country developed, and within three years as many important townships were founded and settled. [=War With the Matabeles=]