These oracle bones, sometimes called dragon bones, were used in a Chinese divination ritual over 3000 years ago. Questions relating to warfare, agriculture and natural disasters would be engraved on the bone before heat was applied with metal sticks, causing it to crack. The diviners interpreted the patterns of the fractures to determine the answer to the question posed. One bone records a lunar eclipse that is precisely datable to 27 December 1192 BC. The darkness caused by an eclipse indicated that an ancestral spirit needed to be pacified.