He later obtained a patent for the manufacture of pressed glass by a process called " Dummer's scallop or coverplate . " By 1840s the glass company was known as P . C . Dummer & Company and was selling glassware for home, decorative and commercial use.
32.
In his examination of beads found at Gedi and the Limpopo Valley ( Mapungubwe ), Schofield placed beads into three categories : red, blue, green, and yellow cylinders made from cane glass; smaller black, red, green, yellow, and blue biconical and lenticular beads made from wound glass; and spheres of red, black, and yellow pressed glass.
