Sacharias Jansen (1580 - 1632)

There appear to be many claimants to the invention of the telescope and compound microscope. The Dutch claim that spectacle makers; Sacharias and his father Hans invented the microscope around 1595 in Middleburg, Zeeland. There is some supporting evidence based on a 1608 patent application. The patent was denied because many similar instruments were available already.
The construction was of 2 tubes that gave a magnification of 10 X. The lens in the eyepiece was bi-convex (bulging outwards on both sides), and the lens of the far end (the objective lens) was plano-convex (flat on one side and bulging outwards on the other side).
This model was made according to a copy of the original one by the Jansen brothers that appeared in an antique shop in Paris in 1891. Its authenticity is today questioned.

Sacharias is credited with the discovery of the telescope.

There is a 1289 Florentine manuscript that refers to corrective lenses for reading. This eventually led to telescopes in 1586. Why such a simple extension of knowledge took so long is unclear. There could be suppression by the Church. Astronomy without the Earth as centre of the Universe was considered heresy. The ability of observing ships and troop movement from long distances, would be a great military and economic advantage. Good reasons for not sharing this knowledge.

 Hans Martens and Maeyken Meertens, Antwerp, Belgium
  1. Sacharias Jansen (Janssen, Janssens), The Hague 1580-1632
      m. 10/23/1610 Catharina de Haene d. 1624
      m. Anna Couget, Antwerp c1625
      1.1 Johannes Sachariassen 1611, m. 1632
  2. Hans Jansen
  3. Sara Jansen