A light weight foam block being substantially rectangular in shape, having horizontal and vertical pairs of tongues and grooves around its perimeter enabling it to interlock with horizontally and vertically adjacent blocks to construct a mine stopping wall.
Danny Damron (1989-1993), Jeff Barnes (1976-1977), Karen Parks (1956-1960), Mary Zachary (1961-1965), Vonda Masters (1951-1955), Ramon Price (1942-1946)