Tag Archives: Bürgi

Johannes Kepler Monument in Weil der Stadt

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Photography by Carlos Dorce

Weil der Stadt is located near Stuttgart. Johannes Kepler was born in this very veautiful town on December 27, 1571 and his memory is still there: this big statue is in the middle of the Market Square…

Photography by Carlos Dorce

Photography by Carlos Dorce

… and Copernicus, Mästlin, Tycho Brahe and Jobst Bürgi are with him in this monumental sculpture.

Photography by Carlos Dorce

Photography by Carlos Dorce

The four scientists are in the corners of the base of the statue and the words “Astronomia”, “Optica”, “Mathematica” and “Physica” are graved on each of the four sides.

Photography by Carlos Dorce

Photography by Carlos Dorce

I must say that here we have the first (imaginary) bust of Bürgi that I know. Bürgi was one of the originators of the logarithms because Kepler said that he had seen Bürgi using logarithms in astronomical calculus (Rudolphine Tables (1627)) before their “official” first occurrence in Napier’s  Mirifici Logarithmorum Canonis Descriptio (1614). Furthermore, Bürgi published his logarithms in his Aritmetische und Geometrische Progreß tabulen (1620) but his “red numbers” and “black numbers” couldn’t never win the “logarithms” which were the first calculator in all history.

Photography by Carlos Dorce

Photography by Carlos Dorce

Notice that this statue is not very similar to this other portrait from 1620:

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J.Bürgi at the age of 67. Drawing by Aegidius Sadeler (1619)

The base of the statue also have four graved images representing moments in Kepler’s life like thispicture with Kepler in the middle explaining the Copernican system…

Photography by Carlos Dorce

Photography by Carlos Dorce

… with Hipparchus and Ptolemy watching how a central Sun brights in the middle of the universe.

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Can you imagine Kepler investigating about his elliptical orbits?

Photography by Carlos Dorce

Photography by Carlos Dorce

Next to Market Square there is his bithplace which hosts… no, no, no! Tomowwor will be another day!

Location: Weil der Stadt (map)

The National Technical Museum in Prague

Photography by Carlos Dorce

Photography by Carlos Dorce

This is one of the Top 10 Museums in Prague! The museum was founded in 1908 and has been in its current location since 1941. It’s a very big building and the collection exhibited is so big although the exhibition about transports is its main attraction:

Photography by Carlos Dorce

Photography by Carlos Dorce

But for me, the exhibition about Astronomy has been the interesting part of the museum and I have been able to visit it on my own meanwhile my children were playing in another room with some technical toys. The astronomical rooms are very dark so it has been very difficult to take good pictures although I’ve tried to do my best. The collections has sundials, armilar spheres, quadrants, astrolabes,… and a lot of other astronomical instruments:

Photography by Carlos Dorce

Photography by Carlos Dorce

For example, the polyhedrical sundials are so beautiful like this constructed on a cube by German David Beringer around 1750:

Photography by Carlos Dorce

Photography by Carlos Dorce

Or… what about this other constructed by Mathias Karl Krausler in 1691?

Photography by Carlos Dorce

Photography by Carlos Dorce

The oldest exhibited astrolabe is this unsigned one from around 1450:

Photography by Carlos Dorce

Photography by Carlos Dorce

And there also is an unsigned torquetum from the late 16th century:

Photography by Carlos Dorce

Photography by Carlos Dorce

One of the instruments which have surprised me has been Joost Bürgi’s sextant for measuring the angles of celestial bodies (I knew that Bürgi, one of the inventor of logarithms, had constructed a lot of clocks and astronomical instruments but I didn’t expect to find one here!). Kepler used it to measure two consecutive oppositions of the planet Mars in 1602 and 1604.

There also is Habermel’s sextant, built by Erasmus Habermel (1538 – 15th of November of 1606 in Prag) who was  mechanic at the court of Emperor Rudolph II:

Photography by Carlos Dorce

Photography by Carlos Dorce

The prevailing opinion for a long time was that the instrument belonged to Brahe and so it was called the “Tychonian sextant”.

Habermel was specialised in small devices and portable sundials and one example is this sundial in the form of a book (c.1600)…

Photography by Carlos Dorce

Photography by Carlos Dorce

… and another is this equinoctial sundial (1585):

Photography by Carlos Dorce

Photography by Carlos Dorce

Finally, look at this armilar sphere from the second half of the 16th century! It’s a piece of art!

Photography by Carlos Dorce

LocationNational Technical Museum in Prague (map)