THE WORKERS IN THE MINES                  61
	Underground work in the mine is carried on both day and night by three shifts, under the supervision of the mine manager and overman and three assistant overmen, one ot whom is detailed to take charge of each shift. The shaft is reached chrough an underground passage leading from the compound, and a partition in this passage gives separate entry and exit ways to and from the mine. All laborers are taken up and down the shafts in cages. Each " boy " wears a number on his wristband for easy identification, and when he passes into the mine his number is taken by a guard, and a tally machine records each native as he leaves the compound to go to work; on his return, daily, he brings a ticket noting in what working gang he was employed and what pay he had earned for the day. The natives commonly work for the contractors, who mine and tram the diamond-bearing ground at a price per load which is arranged by tender, and the natives are paid a fixed wage per diem ; but a worker must drill a certain number of feet of holes for blasting, which in soft ground is about twelve feet, or he must load a fixed number of trucks, in order to earn his daily pay. The natives usually work in the mines in gangs num­bering from ten to thirty men and boys. The limit of age