 Extracting diamonds from rocks, and processing the low-quality gold ore at the Rand, was very labour-intensive and required armies of workers.To offset the cost of employing so many workers, and to compensate for the high salaries offered to machine supervisors and administrators, the companies offered very low wages to ordinary labourers, resulting in falling living standards in urban areas.The need to create a fixed labour force resulted in the colonial government, and the mining corporations, introducing a variety of schemes to keep workers on-site for lengthy periods of time.