Mines may become flooded by the inrush of surface waters in times of great rainfall or sudden floods, or by the undermining of surface waters.
Gold was discovered on the Sweetwater river in 1867, and a large inrush of population followed.
The didactic element was no longer in sole possession of the field, for the inrush of multitudes to the Christian faith and the building of large churches necessitated a return to the evangelical or proclamatory type of sermon.
At the open end, as a first approximation to be corrected later, there are no pressure changes, for any tendency to excess can be relieved by immediate expansion into the outer air, and any tendency to defect can be filled up by an inrush from the outer air.
The first great inrush of population, following the discovery of gold and the opening of the railway, brought many desperate characters, who were held in check only by the stern, swift measures of frontier justice.