Zacharias Janssen - Inventor of the First Optical Telescope

Zacharias Janssen (born between 1580 and 1588, died in 1638) was a famous Dutch inventor and spectacle-maker that is today best known for his associations in the creation of early models of telescope and compound microscope. However, today’s historians cannot find conclusive evidence of Janssen truly being first man that created those instruments, with several clams of discovery that were made even after his death.

Zacharias Janssen was born in Hague, as a son of Hans Martens and Maeyken Meertens who were most probably from Antwerp, Belgium. After birth the family moved to Middelburg, Netherlands, and young Zacharias Janssen grow up on the street, constantly breaking the law and being chased by the authorities. Between age 30 and 35 he was appointed as the guardian of two children of local spectacle maker Loys Lowyssen. During that time, he started to focus his work on creating spectacles, which was very lucrative work that often required spectacle-makers to work in secret and hide their findings from general population. During that time, Zacharias Janssen lived door to door to the spectacle maker Hans Lippershey who is today credited as the creator of the first telescope.

The reason why so many historians cannot be sure about validity of Zacharias Janssen’s claims is because his entire life he had run-ins with the law, and none of his claims received thorough verification. He was accused several times for counterfeiting coins, (as a lens-grinder he had tools and expertise to do that), he was arrested several times, and escaped from law until he managed to get all his charges dropped. Reports of his discoveries were often very conflicting, and they came only from their family or friends. Additionally, almost all records of his life were destroyed in the bombing of Netherlands by Nazis in 1940, but many investigation files managed to be saved (original documents were lost).

Janssen’s claim on Telescope arose at the same time as Hans Lippershey applied for the patent for his telescope. In addition to them two, Jacob Metius of Alkmaar also tried to secure patent claim. None of them received patent, but only Lippershey received award from government for being the first who officially applied for patent. Some reports clearly described that Jacob Metius created telescope first, while Jenssen claimed that his father created first design in 1590. Jassen’s son testified in court that this was true. In the end, none of them were awarded the patent.

Few years after his unsuccessful attempt to patent microscope and telescope, Zacharias Janssen started counterfeiting coins, and from that point he did not work anymore on any new discoveries in the world of the optics.