What German-Dutch spectacle-maker associated with Jacob Metius is associated with the invention of the telescope?
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.
Nonius (device) Nonius is a measuring tool used in navigation and astronomy named in honour of its inventor, Pedro Nunes (Latin: Petrus Nonius), a Portuguese author, mathematician and navigator. The nonius was created in 1542 as a system for taking finer measurements on circular instruments such as the astrolabe. The system was eventually adapted into the vernier scale in 1631 by the French mathematician Pierre Vernier.