Zacharias Janssen

Zacharias Janssen; also Zacharias Jansen or Sacharias Jansen; 1585 – pre-1632) was a Dutch spectacle-maker who lived most of his life in Middelburg. He is associated with the invention of the first optical telescope and/or the first truly compound microscope, but these claims (made 20 years after his death) may be fabrications put forward by his son.

Biography Zacharias Janssen was born in The Hague. Local records seem to indicate he was born in 1585 although a date of birth as early as 1580 or as late as 1588 are also given. His parents were Hans Martens (who may have been a peddler) and Maeyken Meertens, both probably from Antwerp, Belgium. He grew up with his sister Sara in Middelburg, at the time the second most important city of the Netherlands. He was known as a "street seller" who was constantly in trouble with the local authorities. He stated he was born in The Hague on the marriage file of his first marriage, with Catharina de Haene, on October 23, 1610. When this file was refound by Cornelis de Waard in 1906, De Waard found the following excerpt: Sacharias Jansen, j.g. uut Den Haag, "Zacharias Jansen, bachelor from The Hague" Before, it was often thought that Janssen was a native of Middelburg. In 1612, Zacharias and Catharina had a son they named Johannes Zachariassen. In 1615 Zacharias was appointed guardian of two children of Lowys Lowyssen "geseyt Henricxen brilmakers" (called Henry the spectacle maker). It is surmised that Zacharias also took possession of Lowys Lowyssen's spectacle-making tools because the first record of Zacharias Janssen being a spectacle maker appears in 1616. The family had to move to Arnemuiden in 1618 after Zacharias's counterfeiting activities were exposed. There Zacharias was again accused of counterfeiting in 1619, causing him to be on the move again, ending up back in Middelburg in 1621. A year after the death of Janssen's first wife in 1624, he married Anna Couget from Antwerp, who was the widow of a Willem Jansen (probably a relative of Janssen). He moved to Amsterdam in November 1626 with a profession of a spectacle maker, but was bankrupt by 1628. Janssen has been given a death date as late as 1638 although his sister said he was dead in 1632 testimony and his son Johannes declared his parents had died by the time of his marriage in April 1632.

Alleged invention of the telescope and microscope Over the years there have been claims Zacharias Janssen invented the telescope and/or the microscope in Middelburg between 1590 and 1618. Zacharias worked for some time in the very competitive and secretive trade of spectacle-making and at one time lived next door to Middelburg spectacle maker Hans Lippershey, who is also claimed to have invented the telescope. Janssen's attribution to these discoveries is debatable since there is no concrete evidence as to the actual inventor, and there are a whole series of confusing and conflicting claims from the testimony of his son and fellow countrymen. The claim that Zacharias Janssen invented the telescope and the microscope dates back to the year 1655. During that time Dutch diplomat Willem Boreel conducted an investigation trying to figure out who invented the telescope. He had a local magistrate in Middelburg follow up on a 45 year old recollection of a spectacle maker named "Hans" who told a young Boreel in 1610 about inventing the telescope. In his investigation the magistrate was contacted by a then unknown claimant, Middelburg spectacle maker Johannes Zachariassen, the son of Zacharias Janssen, who testified under oath that his father invented the telescope and the microscope as early as 1590 and that Hans Lippershey had stolen his father's invention of the telescope. This testimony seemed convincing to Boreel, who modified his recollections, concluding that Zacharias must have been who he remembered. Boreel's conclusion that Zacharias Janssen invented the telescope a little ahead of spectacle maker Hans Lippershey was adopted by Pierre Borel in his 1656 book on the subject. In Boreel's investigation Johannes also claimed his father, Zacharias Janssen, invented the compound microscope in 1590. For this to be true (Zacharias most likely dates of birth would have made him 2–5 years old at the time) some historians concluded grandfather Hans Martens must have invented it. Other claims have come forward over the years. Physicist Jean Henri van Swinden's 1822-23 investigation reached the conclusion supporting Janssen and in 1841 a collector named Zacharias Snijder came forward with 4 iron tubes with lenses in them purported to be Janssen original telescopes. In historian Cornelis de Waard's 1906 book on the history of the telescope he recounted his discovery of a note written in 1634 by the Dutch philosopher Isaac Beeckman in which Beeckman mentioned that Johannes Zachariassen claimed his father created his first telescope in 1604 (and that it was a copy of an Italian device from 1590). The German astronomer Simon Marius's account to his patron Johan Philip Fuchs von Bimbach about meeting an unnamed Dutchman at the 1608 Autumn Frankfurt Fair who tried to sell him a device that sounded like a broken telescope has led to later speculation this unnamed Dutchman could have been Zacharias Janssen.

Controversy

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