Johannes Hevelius
Early Life:
Born on
January 28, 1611, Johannes Hevelius was one of the leading astronomers of his
time. He studied at the University of Leiden where he studied jurisprudence,
the theory of law, and spent his free time studying Astronomy. After his
studies, Hevelius spent many years traveling around Europe, specifically to
France and England, to consult many astronomers of the time. After he returned
to his native town of Danzig, he took over the family business of brewing and began
to study municipal administration with which he became town councilor in 1651. Hevelius
dedicated his life to astronomy until his death on his seventy sixth birthday,
1687.
Career:
After he
returned to his hometown, Hevelius used some of his family’s wealth to buy two
houses adjacent to his own and he begun construction of his instruments. In the
prime of his career, Hevelius built a keplerian telescope that had a focal length
of 150 feet. Made from just wood and wire, this telescope’s performance was
impacted by the wind and sometimes even by the heat of the day. On the twenty
sixth of September, 1679, while Johannes was out of town, a fire broke out in
one of his three adjacent houses. Unfortunately the fire destroyed all three
houses including all of his instruments and his almost completed book. Hevelius
later rebuilt his instruments but they were never as accurate as his earlier instruments.
Despite the setback, he continued his research and eventually finished his
book. Hevelius is most known for his lunar
topography, the mapping of the moon’s surface, which he made about sixty
precise drawings. He is also well known for his mapping of sunspots and his
discovery of many comets and messier objects. In one of his last published
books, Hevelius created new constellations, eleven of which are still used
today.
Legacy:
Hevelius’s
instruments were some of the most extensive, most accurate of the time period.
His one hundred fifty foot home made telescope was a feat of engineering. Despite
the resources and time Hevelius spent building the telescope, he didn’t believe
telescopes made observations more accurate. As seen with his discussions with
another leading astronomer, Robert Hooke. Hevelius proved mathematically that
his observations we marginally more accurate than one made with a telescope.
Many historians today believe this was because of the quality of Hevelius’s
personal instruments and his skills as an observer rather than the accuracy of
the telescope.
