While bronze vessels were the most visible implements used in the ancestor rites of the Shang dynasty (approx. 1600-1050 BCE), it was through oracle bones that actual communication with ancestors took place. These bones, primarily the shoulder blades of cattle and the undershells of turtles, were dried and had holes drilled in them at regular intervals.
A question was directed to an ancestor by applying a hot poker to these holes to make the surface crack. Specialists, usually a king or a members of a ruling family, would then read the appearance of the cracks to obtain the ancestor's response. Both the question—in positive and negative forms—and the results were written on the surface of the oracle bone.
A vast "library" of these bones has been found near the Shang capital of Anyang in Henan province, China. More than forty-five thousand of them have been published so far. Most foretell births, deaths, rainfall, good harvests, the outcome of hunts and battles, and the meanings of dreams.