Dear Mike, Hal and all,
I am sorry that I could not respond earlier to Mike's posting.
Last year I wrote an article about a related question, from which I have
some relevant information, perhaps also for Hal :-)
1) The earliest evidence for pole-style dials in Europe.
The only author who did extensive research in archives of monasteries,
libraries etc. is Zinner, I think.
Zinner (in "Deutsche und Niederländische Astronomische Instrumente des
11.-18. Jahrhunderts", 1956, p.55) mentions a folding sundial from 1417. He
refers to his book "Die Frankische Sternkunde im 11. bis 16. Jahrhundert"
(1934, p. 56), which I just got from the library. He quotes Georg Hartmann
(instrument maker and researcher in Nuremberg), who wrote in 1544 that he
received this sundial from Duke Ott-Heinrich, dated 1417, who ordered a
copy. It was a cross dial; the cross unfolded in the equatorial plane, so
that its edges pointed to the celestial pole. How reliable the quoted date
is? Zinner refers to a book of collected letters, edited by Johannes Voigt
from 1841, which I don't want to go after...
Zinner (1956) found manuscripts giving instructions for the construction of
pole-style dials from 1426 onward. So my conclusion is that the pole-style
principle appeared in Europe around 1400.
2) The Arabic connection.
The sundial at the Umayyad mosque in Damascus from 1371 (mentioned in
earlier postings) has been described by Louis Janin in Centaurus 16 (1972),
p. 285-298 (including a photo). It incorporates three sundials. The one for
equal hours uses a pole-style. It is a high-point of Arabic gnomonics, and
apparently the result of a long tradition. So the pole-style principle was
known to the Arabs long before 1371, but was only used by astronomers.
The odd story of this sundial: the Egyptian astronomer At-Tantawi noted in
1876 that it was not level and not properly aligned anymore. When he tried
to correct this, the marble dial face (1x2 meter) broke. He made a copy,
which is quite accurate, as is apparent from comparison with three large
pieces of the original. These are now in the National Museum in Damascus.
3) Was the pole-style principle brought to Europe from Arabia, for instance
by returning crusaders?
Karlheinz Schaldach, in BSS Bulletin 1996 nr. 3, p. 32-38, thinks not. He
gives 3 arguments:
a) The first Latin author (or at least one of the first) writing on the
construction of equal-hour sundials, gives no hint that he obtained any
ideas from Islamic contemporaries.
b) There are almost 100 texts on sundials of the 14th and 15th centuries,
proving a great effort in understanding sundial principles, but none giving
the correct solution of the pole-style.
c) There are some 'sun-trials' from that period, showing a 'trial and error'
process.
4) What is the oldest still existing pole-style dial?
a) Fixed dials.
My article addressed the question: What are the oldest, dated or datable,
fixed sundials? It appeared in the Bulletin of the Dutch Sundial Society
2004 nr. 1, p. 15-18, and nr. 2, p. 25-29. The focus was on the sundial at
St. Jacob's Church in Utrecht (NL), which is dated 1463. Zinner, in his
extensive catalog "Alte Sonnenuhren an Europaeischen Gebaeuden" (1964) gives
in the introduction a list of 27 modern sundials of the 15th century. With
'modern' he means reading equal hours, which implies a pole-style. Utrecht
is nr. 7 in this list. With help of Karl Schwarzinger, who takes care of the
Austrian database, and Willy Bachmann, who maintains the database of German
sundials, I was able to check the list, remove some and add some others, and
to get pictures of each. My list of the six oldest dials is as follows:
1446, Weissenfels (Germany), stone-carved, dated
1447, Klosterneuburg (Austria), stone-carved, dated
1452, Hall (Austria), painted, datable
1454, Waldhausen (Austria), stone-carved, dated
1457, Duderstadt (Germany), stone-carved, dated
1463, Utrecht (Netherlands), stone-carved, dated.
'Datable' means: a reliable written source exists, and the stylistic
appearance of the sundial fits the period.
The list should be considered with some reserve, though. Dated medieval
sundials (with a horizontal rod as gnomon) may have been upgraded to a
pole-style dial later, or the carved date may have been changed at later
restorations. Perhaps antedated, to impress neighbouring parishes? Also,
documents may surface some day documenting an earlier date for as yet
undated dials.
b) Portable dials (travel or table-top).
I have not researched this question. Karl Schwarzinger sent me a pretty
folder with color pictures of many beautiful Austrian sundials. Among these
is a folding dial ('Klappsonnenuhr') from 1451, possibly made by Georg
Peuerbach and now in the Kaiser Maximilian Museum in Innsbruck. Does anyone
know of an older portable dial?
Best regards,
Frans Maes
53.1N, 6.5E
www.fransmaes.nl/sundials/
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <sundial@rrz.uni-koeln.de>
Sent: Monday, January 17, 2005 11:19 PM
Subject: Earliest Sundial
> During a short trip to Turkey and Greece last year I visited the Topkapi
> Palace in Istanbul. The exhibit "Science and Technology in Islam"
contained some
> instruments from the Museum of the Institute for the History of
Arabic-Islamic
> Science at the Johann Wofgang Goethe University in Frankfort Germany. One
> was a reproduction of the pole style sundial in Damascus referred to by
Fer de
> Vries. It was identified as "Sundial made by the astronomer Ibn-shajlr (d
> 1375CE) for the Unmayyad mosque in Damascus. Original is in three pieces
and is
> in the National Museum of Syria in Damascus". Photography was not allowed
but
> I managed to take one photo without flash so it is not too clear! It will
be
> part of my sundial talks.
>
> In the palace garden there was another similar sundial with a wire pole
style
> as well as a perpendicular shadow casting object. Photography was easier
> except that the dial was supported far enough above the ground that a
ladder was
> needed to take useful photographs! The plaque states "According to the
> inscription at the edge, the sundial dates from the reign of Sultan
Mehmed II (1451
> - 81) and was restored in 1794 during the reign of Sultan Selim III
> (1789-1807) by Armourer Seyyid Abdullah. The sundial is aligned north
south. The
> face has two gnomons and three different dials."
>
> Hal Brandmaier
>
-
