Hans Lippershey that time he became a master lens grinder and spectacle maker and established a shop. He remained in Middelburg until his death, in September 1619. Hans Lippershey is known for the earliest written record of a refracting telescope, a patent he filed in 1608. His work with optical devices grew out of his work as a spectacle maker, an industry that had started in Venice and Florence in the thirteenth century, and later expanded to the Netherlands and Germany. Lippershey applied to the States General of the Netherlands on 2 October 1608 for a patent for his instrument ""for seeing
Adriaan Metius and developed a special form of Jacob's staff. In 1585, his father had estimated the ratio of a circle's circumference to its diameter, later called pi, to be approximately . Metius later published his father's results, and the value is traditionally referred to as Metius' number. The lunar crater Metius is named after him. In Vermeer's painting "The Astronomer" (1668), the book lying on the table has been identified as a 1621 second edition of Metius's "Institutiones Astronomicae Geographicae". It is opened to Book III, where "inspiration from God" is recommended for astronomical research along with knowledge of geometry and