Zacharias Janssen

Zacharias Janssen ( also Sacharias Jansen, Zacharias Jansen wrote, * 1588 in The Hague; † around 1631 in Amsterdam ) was a Dutch optician, who lived largely in Middelburg.

Life and work

Janssen was a Greek -born ( Ioannidis > Janssen ), capable optician and peddlers ( Dutch: Marskramer ), who had learned his craft from his father Hans Janssen. Through his work as a peddler, he traveled a lot, and later he operated in Amsterdam a company, but went bankrupt. Also Janssen was known as a forger of copper, gold and silver coins. Thus he often came into conflict with the court and was convicted.

Janssen taken in conjunction with the invention of the telescope. On September 25, 1608 patent was requested for the invention of the telescope by Hans Lippershey. In October 1608 a patent was again requested that Janssen is attributed. A short time later by Jacob Matius entitlement to a patent has been charged. Lippershey demonstrated his invention at Prins Maurits in The Hague, although he did not obtain the patent.

A year later, in 1609, Galileo Galilei came with his home-made telescope to the public.

Zacharias Janssen's son, John Zachariassen should swear under oath later that Hans Lippershey, also from Middelburg, stole his father's idea for the telescope have.

The first microscope Janssens was a simple tube with lenses at the end. The increase ranged from three to nine times, depending on the size of the aperture.

Further Reading

• Daniel Boorstin, De ontdekkers. De zoektocht van de mens en zijn naar zichzelf wereld. Elsevier, Amsterdam, 1987. ISBN 90-10-05931-6