Sacharias Jansen

Zacharias Jansen
Sacharias Jansen
Born	The Hague
Citizenship	Dutch
Fields	Optics: Microscopy, Telescopy
Academic advisors	Academic : Academy of the name Sacharias doctoral_students =
Known for	Early innovations in microscopy and telescopy

Zacharias Jansen (c. 1580 - c. 1638) was a Dutch spectacle-maker from Middelburg credited with inventing, or contributing advances towards the invention of the first telescope. Jansen is sometimes credited for inventing the first truly compound microscope. However, the origin of the microscope, just like the origin of the telescope, is a matter of debate.

His name is often written as Zacharias Jansen or Zacharias Janssen, but as Dutch scientific literature writes the name as Sacharias Jansen, that way of writing it is also used in this article.

In 2008, the Netherlands commemorated the 400th anniversary of the telsescope, honoring Jansen as one of the two possible inventors, the other being Hans Lippershey.

Jansen's life

Zacharias Janssen's life was documented by the many investigations on the subject before the Second World War. Many of the Middelburg archives were destroyed by a devastating bombardment on May 17, 1940, during the Nazi invasion of the Netherlands. If there had never been profound investigations, we would not know anything of Janssen's life at all, since all files were lost in the fires following the bombardment. When investigating Janssen's life, a book written in 1906 by Cornelis de Waard, De Extenso, is essential.

All data below is explained in a wider context in a book by Huib J. Zuidervaart of the Vrije Universiteit in Amsterdam that is to be published in the spring of 2008.

Breaking the law

In the years 1613-1619, Janssen was tried several times for counterfeiting coins. Janssen grew up right next to the Middleburg mint where his brother-in-law worked. These circumstances made it very easy for Janssen to mimic the process of manufacturing money. He fled to the neighbouring village of Arnemuiden to avoid the high penalties for counterfeiting coins.^[1]

However, he continued counterfeiting coins in Arnemuiden. In 1619 he was apprehended for owning several devices he counterfeited coins with. Normally, one would have been sentenced to death for this crime. However, since the father of the Arnemuiden bailiff was found to be an accessory, it turned out better for Jansen. Thanks to this, the process was delayed to such an extent that Janssen was able to flee yet another time. Eventually, the case was dismissed. Janssen returned to Middleburg in 1621.^[1]

Inventions

This section requires expansion.

Telescope

According to some historians^[who?], it was not Lippershey, but rather Jansen who invented the telescope. An important source is William de Boreel, who visited Middelburg to research the invention in 1655. Among his interviewees were Jansen's son and daughter. Boreel concluded that Jansen's telescope was finished about 1610. His research was referenced by Pierre Borel in De vero telescopii inventore.^[2]

The fact that Jansen is not well-known outside the Netherlands has to do with the patent Lippershey requested for the telescope in 1608. Whilst that news was spread across the world in just a few months (eventually Galileo Galilei heard about it), several investigations on the subject in the 17th, 18th, 19th and 20th century, stating Jansen might have invented the device, were only published and read in the Netherlands. To make it even worse, just one of the investigations was published in English and just that one stated Lippershey did invent the telescope, making Jansen even more infamous in countries outside the Netherlands. Several sources, however, indicate Sacharias Jansen constructed the first telescope in 1604, or even earlier.^[1]

Microscope

Jansen invented a single-lens (simple) microscope, probably with the help of his father, in 1595^[3] while trying to find a way to make magnification even greater, to help people with seriously poor eyesight. Jansen's attribution to this discovery is debatable.

References

External links

• Website about the 400th anniversary of the telescope
• Lens Crafters Circa 1590: Invention of the Microscope, American Physical Society