Defective memory and speech led him to give up both the study of divinity and his fellowship in 1603, in order to devote himself to mathematics and chronology.
In 1629 or 1630 he became surety for the debts of his brother, and being unable to pay was committed to prison, first in the Bocardo Prison at Oxford, and subsequently in the King's Bench, where he pursued his studies, spending what money he could upon books.