He analyzed sunspot records (and approximated records), comparing them to riots, revolutions, battles and war in Russia and seventy-one other countries for the period 500 BCE to 1922 CE. (A process known as historiometry.) He found that a significant percent of what he classified as the most important historical events involving large numbers of people occurred around sunspot maximum.
He studied sunspot records and estimated data, linking them to riots, revolutions, battles, and wars in Russia and seventy-one other countries from 500 BCE to 1922 CE. (This method is called historiometry.) He found that a considerable number of major historical events involving many people occurred around times of high sunspot activity.