Jacob Metius

Jacob (Jacobus; sometimes James) Metius (after 1571–1624/1631) was a Dutch instrument-maker and a specialist in grinding lenses. He was born and died in Alkmaar and was the brother of Adriaan Adriaanszoon (simply called Metius). He is one of three people associated with the invention of the telescope, the other two being Hans Lippershey and Zacharias Janssen. Not much of him is known besides his 1608 patent application for the invention. He died in Alkmaar between 1624 and 1631. Metius may have made many inventions but kept them secret. Before his death he destroyed them all to prevent anyone else from claiming them.

In October 1608, the States General discussed Jacob Metius's patent application for a device for "seeing faraway things as though nearby," consisting of a convex and concave lens in a tube, and the combination magnified three or four times. His use of a convex objective lens and concave eyepiece may have been a superior design to Hans Lippershey telescope design which was submitted for patent only a few weeks before Metius'.

Metius informed the States General that he was familiar with the secrets of glassmaking, and that he could make an even better telescope with the government's support. When Metius perceived that the States General was reluctant to review his claim, he prohibited anyone from seeing his telescope.

The States General voted Jacob Metius a small award, although it ended up employing Lippershey to make binocular versions of the telescope. At his death, Metius’ tools were destroyed according to his wishes in order to prevent anyone from claiming the honor of inventing the telescope.

There is a claim by Johannes Zachariassen, Zacharias Janssen's son, that Jacob Metius and Cornelis Drebbel bought a telescope from him and his father in 1620 and copied it, although this is well after the dates Metius is known to have been making telescopes. One version is stated in Charles Hutton's 1795 book Mathematical and Philosophical Dictionary :