[2] His mining experience began with a survey of the salt deposits on Carmen island off the coast of Mexico, followed by appointment as engineer to a syndicate in search of gold and silver in northern Nevada.

He then (before June 1873) became an assistant assayer in the US branch mint in San Francisco, and spent 3+1⁄2 years as superintendent of the Meadow Valley Mining Company at Pioche, Nevada.

Under pressure from Rhodes, he agreed to forget about gold and move into the field of diamonds, and finally accepted an appointment as manager of De Beers in Kimberley in May 1887.

The result was the formation on 13 March 1888 of the De Beers Consolidated Mines Co., with Rhodes, Barney Barnato and Alfred Beit on the board.)

Walking about was exceedingly dangerous and unpleasant, and there was a never-ending worry that the workings might collapse, with serious consequences for the lives of the workers and the financial success of the operation.

Rhodes had great confidence in his undoubted administrative skills and his talent for financial management, and drew him into the grand scheme of consolidating all the diamond mines under De Beers.

In 1902 he published the comprehensive tome The Diamond Mines of South Africa; some account of their rise and development (NY: Macmillan Co, 1902) with later revised editions in 1904, 1905 and 1906 comprising 2 volumes.

[9] In recognition of his achievements, the Royal Academy of Science in Sweden awarded him its silver medal in 1905, and the University of California an honorary doctorate of laws in 1910.