Madame Midas by Fergus Hume — Read

At the foot of the huge mound of white mulloch which marked the site of the Pactolus Mine was a long zinc-roofed building, which was divided into two compartments. In one of these the miners left their clothes, and put on rough canvas suits before going down, and here also they were searched on coming up in order to see if they had carried away any gold. From this room a long, narrow passage led to the top of the shaft, so that any miner having gold concealed upon him could not throw it away and pick it up afterwards, but had to go right into the searching room from the cage, and could not possibly hide a particle without being found out by the searchers. The other room was the sleeping apartment of such miners as stayed on the premises, for the majority of the men went home to their families when their work was done.

There were three shifts of men on the Pactolus during the twenty-four hours, and each shift worked eight hours at a time -- the first going on at midnight and knocking off at eight in the morning, the second commencing at eight and ending at four in the afternoon, and the third starting at four and lasting until midnight again, when the first shift of men began anew.