Which microscope did Robert Hooke use to study tree bark

Robert Hooke is a scientist known for his fine skills in drawing and on his work on different instruments. He is considered as a Renaissance Man. He was a jack of all trades and a master of many. In fact, he built his own compound microscope to study the thin slices of cork. He examined the cork from the bark of the cork oak tree. He found out that the cork is made up of small rooms that are dead. These small rooms were referred by him as "cells".