Transcript Ottoman Sundials

Ottoman Sundials
Roger Bailey
NASS, St Louis, 2008
Ottoman Sundial
Topkapi Palace, Istanbul
• Sundial in Third
Garden of Topkapi
Palace, near Library of
Ahmet III.
• Designed by Suleyman,
the first secretary of
the Treasury in the
reign of Memhet II,
the Conqueror (14531481)
• Renovated in 1794 by
Seyyid Abdullah
Ottoman Sundial
Missouri Botanical Garden
• Topkapi Dial design for
Ottoman Garden at
Missouri Botanical
Garden, St Louis
• Paul Brockman: Project
Coordinator
• E.L. Bakewell Jr: Sponsor
• Fazil Sutcu: Architect
• Abraham Mohler:
Sculptor
• Roger Bailey: Designer
15th Century Superpowers
•
•
•
•
•
•
•
Holy Roman Empire? Fredrick III,
Spain? Isabella & Ferdinand
England? 1485 Henry VII, War of Roses
France? Louis XI (the Prudent)
Florence?, Medici, Papal States? Borgia
China? Ming Dynasty (1368-1644)
Ottoman? Mehmet II (the Conqueror)
http://en.wikipedia.org/wiki/List_of_state_leaders_in_1480
Mehmet the Conquorer
• Constantinople, centre
of the world, where
East meets West
• Ottoman Turks took
Constantinople in 1453
• Ended Byzantine
Empire started by
Constantine in 330
• Expanded Ottoman
Empire in Middle East
and Eastern Europe
Battle of Walachia 1462
• Count Dracula of
Transylvania, Vlad III
(the Impaler), rebelled
and fought back in
Walachia in 1462
• Impaled 20,000
Turkish prisoners
• Vlad captured and
executed but stopped
the Ottoman advance
across Europe
Battle of Lepanto 1571
Ottoman navy defeated by Don Juan and
combined fleet of Holy League
Mehmet II
• Sultan 1453-1481
• Emperor, warrior,
scholar
• Built Istanbul:
Topkapi Palace
• Converted Hagia
Sophia to a mosque
Topkapi Ottoman Sundial
• Drawn by Suleyman
Bey, Secretary of the
Treasury for Sultan
Mehmet II
• Similar to sundials at
Damascus & Kairouan,
Tunisia
• Two gnomons, four
time systems
• Represents science,
culture, religion, and
empire
Hagia Sophia: Istanbul
Byzantine Cathedral: “Divine Wisdom”
Roman Emperor Justinian 537
1453’s Sultan’s Mosque, now museum
Hagia Sophia: Istanbul
Topkapi Palace, Istanbul
• Build by Mehmet II on ruins of Byzantine palaces
• Palace, harem, government center, gardens
• Ottoman sundial in Third Garden
Topkapi Ottoman Sundial
Topkapi Palace
Ottoman Sundial
Ezanic Hours
Italian
Babylonian
Asr
Outer Scale:
Polar Sundial
Hour Lines:Angles
Tan (Hour Angle) = Tan (time angle) x Sin (latitude)
Polar Gnomon Support
Hour Scale: Based on Noon as 6 o’clock. Ottoman Turk Numbers
Ibn al-Shatir ‘s Sundial
Damascus Umayyad Mosque
Replica in Damascus Museum
• Horizontal sundial on north
Minaret until ~1900
• By Ibn al-Shatir in 1371
• Astronomer, mathematician,
timekeeper (muwaqqits)
• Planetary theory like
Copernicus
• First polar sundials including
Compass Compendium
• Showed time relative to
sunset, sunrise, noon and
afternoon
• Model for Ottoman sundials
Ezanic Hours
At sunset, day ends 12 and starts at 0
Summer 21 June
Vertical Peg Gnomon
11
Date Lines:
Shadow path
On solstices
and equinox
12
1
2
10
Tip of shadow
tells time
5
3
Winter 21 June
11
Ezanic Hours: Sunset 12 off scale to east (left) 24 in Italian Hours
Babylonian Hours: Sunrise 12 off scale to west(right). Mirror image
4
Moslem Prayer Times
Asr starts when shadow length is noon shadow + gnomon height
Asr ends when shadow length is noon shadow + twice gnomon height
Ibn al-Shatir Sundial
Kairouan, Tunisia
Great Mosque
http://astrotunisie.one-forum.net/culture-astronomique-f6/les-cadrans-solaires-en-tunisie-t31.htm
Kairouan, Tunisia
• Great Mosque
• Sundial designed
in 1842 (1258 H)
by Almed Essoussi
• Four peg gnomons
• Inspired by Ibn
al-Shatir dial in
Damascus and
Topkapi dial
Kairouan Mosque Sundial
Istanbul: New Mosque Yeni Camii
Veni Camii
Vertical Declining Sundials
Polar Gnomon
bent horizontal
(Moslem style)
New Mosque
Yeni Camii 2
Local hours 20’
New Mosque
“Yeni Camii” 1
-Local hours 20’
-Ezanic hours
-Asr 1 & 2
-Zhur?
-Declination
New Mosque
Yeni Camii 3
Islamic sundial
Prayer times
Hours? 20’
Overlay confirms
declination lines,
equinoctial and Asr
Prayer line (N + G).
Zuhr Prayer line and
parallel curved time lines
are different
Why? Ottoman Sundials
• Complex and difficult to read but
impressive
• Four time systems:
•
•
•
•
– Time systems from east and west
– Religious and secular time
Call to prayer? Tell time? Perhaps
Understand and explain our universe?
Teach & demonstrate scientific prowess
Demonstrate the scope of the Empire
Missouri Botanical Garden
Missouri Botanical
Garden
• St Louis, Missouri
• Ottoman Garden
– Same Latitude as
Istanbul
– Exotic tulips
– Water features
• Ottoman Sundial
• NASS Conference
– Fred Sawyer NASS
– Don Snyder NASS
– Mike Olsen MBG
Ottoman Sundial
• Topkapi Dial design for
Ottoman Garden at
Missouri Botanical
Gardens, St Louis
• Paul Brockman: Project
Coordinator
• Fazil Sutcu: Architect
• Abraham Mohler:
Sculptor
• E.L. Bakewell Jr:Sponsor
• Roger Bailey: Designer
Differences: Topkapi and Missouri
• Goal: Comprehension not confusion
• Noon is 12 not 6 on polar dial
• Arabic not Ottoman numbers
• Fewer Lines
– Time division: 5’ 15’ 30’ not 1’ 4’ 20’
– Hours & Half hours (30 min) , not 20 minutes
• Prefered view: from South
• Latitude 41 vs 38.6
Fer de Vries: ZW 2000
A UNIFORM METHOD TO COMPUTE FLAT SUNDIALS
• Principle: Convert the sun's position into coordinates for
a shadow point on the dial's face
• Solve for Altitude and Azimuth knowing Latitude for
various times, Declinations, sundial types and
orientations
• Project the shadow of a point, the tip of a perpendicular
gnomon onto the plane of the dial
• Draw the timelines required
• Clip drawing or export as a DXF file
• Design the sundial, based on the timelines timelines
http://www.de-zonnewijzerkring.nl/eng/index-vlakke-zonw.htm
Polar Sundial Design
Ottoman Sundial for Local Solar Time
• Outer dial with the polar
gnomon is a simple standard
Western design
• Create the lines at the
correct angles for the location
using specific sundial design
software “ZW 2000” by Fer
de Vries
• Bring the lines into a CAD
program “Delta CAD” to trim
and fit to design
Ezanic Sundial : Sunrise
North
Babylonian Hours are the reverse of Italian
West
6
3 4
Hours
from
Sunrise
8 10
2
East
12
1
Peg Gnomon
1
South
Winter AM 2 hours after sunrise
Sunrise 12 &0 off scale to West (left), 24 in Babylonian Hours
Ezanic Sundial : Sunset
North
West
3
2
11
East
4
5
10
6 7
Date Lines:
8 9
Equinox
1
Hours 12
from
previous
11
Sunset
Winter 21 December
Shadow path
On solstices
and equinox
Peg Gnomon
South
Summer 21 June
Ezanic Hours: Sunset 12 off scale to east (right) 24 in Italian Hours
Ezanic Timelines Simplified
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•
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•
Timelines seem confusing but are quite simple
Go back to the Bible: Third, Sixth, Ninth Hour etc.
Look at the Equinox, 12 hour days, mid-day is 6
All the hours are the same, crossing on the Equinox
East
West
1
Equinox 2
3 4 5 6 7 8 9
12
11
10
11
12
Red: Italian Sunset
Blue: Babylonian
1
Moslem Prayer Hours
• For devout Moslems, there are five prayer times,
all determined by the altitude of the sun
– Fajr (morning): twilight to dawn
– Zuhr (noon): Shadow length: noon + ¼ gnomon height
– Asr (mid pm): Shadow length: noon + gnomon height to
noon + 2 gnomon heights
– Maghrib (sunset): sundown to end of twilight
– Ish (night): twilight to dawn
• Zuhr and Asr are (were) set by shadow lengths
• Horizontal sundials with perpendicular gnomons
Sext zuhr
Midday
Moslem
Triece
duha
Daily
Prayer Times
Monastic
Nones
asr
Vespers
Sunset maghrib
Nightfall
Compline
isha
Prime Sunrise
fajr Daybreak
Matins
Midnight
Moslem Prayer Times
Defined by altitude of sun
determined by shadow lengths
Zuhr = Noon + ¼ gnomon height
Asr = Noon + gnomon height to
Noon + 2 gnomon heights
Gnomon
Noon Zuhr
Asr
Moslem Prayer Timelines
Zon 2000
Istanbul: Latitude 41º N
Horizontal with Vertical Gnomon
Qibla: Direction to Pray
Qibla: N 47.2º E
Direction to Mecca
• Moslems pray towards
Mecca, generally East
• The direction is as important
as the time
• Mihrab (niche), in the
Mosque is oriented to Mecca
• Ottoman sundials often show
the Qibla direction
• This symbol represents
the Mosque, Mihrab & Qibla
• Great Circle Qibla St Louis
to Mecca is N 47.2º E
63.22
Gnomon 2
Support
31.62
9
11
10
12
1
2
3
38.87
North
Noon
8
4
11
Winter Solstice
21 December
26.35
30.00
4
3
10
5
6
2
7
8
Western Hours based on 12 noon
Italian Hours based on 12 Sunset
9
Babylonian Hours based on 12 Sunrise
West 1
Moslem Afternoon Prayer Times
East
7
5
12
Gnomon 1
5 cm Peg
East West Line 12
Italian & Babylonian
11
12.52
Asr 1: Noon Shadow + Gnomon Height
Asr 2: Noon Shadow + 2 x Gnomon Height
Summer Solstice
21 June
South
Gnomon 2 Polar Rod 38.6º
6
Zuhr: Noon Shadow+ 1/4 Gnomon Height
7
6
7
Qibla: N 47.2º E
Direction to Mecca
76.20 cm
30 inches
76.20 cm
30 inches
Full Size on E drawing (44" x 34")
Ottoman Sundial
Missouri Botanical Gardens
MBG 2: Description R3 4 Mar 2008
Walking Shadow Designs
Ottoman Sundial
Gnomon Details
MBG 4 R4 7 Mar 2008
Walking Shadow Designs
Gnomons: Polar & Peg
2.00
1.00
Full Size on D paper, 34" x 22"
Dimensions in centimeters cm
.69
2.45
.71
2.82
33.95
Polar Gnomon
6mm (.25")
Bronze Rod
.73
3.24
.75
3.72
58.60
54.41
Gnomon
Support
Bronze
4.28
.77
Each ring diameter is15%
more than the ring above
4.93
.79
Rings are elipses
width = 85% height
5.66
.81
Vertical Gnomon
5 cm high
Bronze
.30 DIA
1.50
5.00
3.00
1.23
1.23
2.00
2.00
4.17
1.36
1.00
.80
5.00
4.00
38.6°
6.00
12.50
42.50
35.56
30.00
38.10
15.00 cm
6"
Marble Base for Sundial (28" x 28" x 6")
73.66 cm
28"
Gnomon Support
Rotated 90º
To Show Rings
Bronz
Two Gnomon Problem
• ZX 2000 does all the
required timelines but
for one gnomon height
• Polar gnomon is 10 cm
at origin, peg gnomon
is 5 cm
• Do two designs and
merge DXF files
Vert
5 cm
Bron
.30 DIA
5.00
3.00
1.36
.80
4.00
38.6°
12.50
35.56
Merge DXF Files
End of First DXF
*
*
VERTEX
8
L_A
10
0.0000
20
-12.5193
0
SEQEND
8
L_A
0
ENDSEC
0
EOF
Start of Second DXF
0
SECTION
2
ENTITIES
0
LINE
8
L_$
10
-2.5000
20
85.0000
*
*
*
*
File Conversions
1.Rename ZW *.dxf
as *. Txt
2. Edit as *.txt
3. Save and rename
*.txt as *.dxf
4. Import into CAD
5. Trim lines to
design in CAD
6. Print final as pdf to
print full size at any
copy shop
Construction: Abraham Molher
11 March – Marble
1 April – Carving
7 April – Gnomons
9 May – Installation
16 May -Dedication
Correction to Clock Time
Equation of Time + Longitude Correction
20.00
15.00
Equation of Time
Correctiion to Clock Time (Min)
10.00
+Longitude
5.00
0.00
04/ Dec 07
02/ Feb 08
02/ Apr 08
01/ Jun 08
Date
-5.00
-10.00
-15.00
-20.00
31/ Jul 08
29/ Sep 08
28/ Nov 08
27/ Jan 09
Orientation Error!
• After careful design, engraving,
construction and alignment with
the sun, the dial was arbitrarily
reoriented
• It “looks better lined up with
the sidewalk”, ~ 9º off North
• Errors are significant:
–
–
–
–
14 to 37 minutes
Worst when shadows are long
Winter, early AM and late PM
Error obvious from date lines
Orientation Error Check
• Dial Reads 10:17 Solar
• Picture taken 11:31 CDT,
5 July by Don Snyder
• Corrections to clock
– Daylight savings -1:00:00
– Equation of Time -4:41
– Longitude 25’15”
-1:02
• Clock to Solar 10:25
• Observed Error 8 min
• Predicted Error 15 min
Sundial Orientation Error: 7.5º
Missouri Botantical Garden
35.00
30.00
Winter
Error (Min)
25.00
20.00
15.00
Summer 23.44º
Dec 12º
Equinox 0º
Dec= -12º
10.00
Winter -23.44º
Summer
5.00
0.00
0:00:00
Sunrise
2:24:00
4:48:00
7:12:00
Noon
9:36:00
12:00:00
Time
Sunset
14:24:00
16:48:00
19:12:00
21:36:00
Reorientation Design
N
9
10
11
12
1
2
3
4
11
4
8
3
10
5
2
6
7
8
9
1
7
5
12
11
• Dial oriented to
polar axis
• Stone oriented
to Garden axis,
7.5º east
• Outer dial scale
oriented with
stone
Stone is off North axis by 7.5º East
6
6
7
5
Size on E drawing (44" x 34") 28 inch square Marble Base
8
Ottoman Sundial
Missouri Botanical Gardens
MBG 7.5 Template RO-1 Aug 1 2008
Walking Shadow Designs
Reorientation Design
• Dial oriented to
polar axis
• Stone oriented
to Garden axis,
7.5º east
• Outer dial scale
oriented with
stone
Proud Artisans
• Abraham Mohler
Sculptor
• Roger Bailey
Designer
Ottoman Sundial
Missouri Botanical Garden
• Sundial is unique and
significant
• Only Islamic dial in
public use in America
• Only dial with Italian
and Babylonian hours
• Only dial with prayer
times or Qibla
• Shows what western
civilization gained
from the peak of
Islamic science and
culture
• Appropriate for the
Ottoman Gardens
Islamic Culture and Science
Astronomy and Mathematics
•Astronomy
•Arabic names for stars
•Babylonian Deg:Min:Sec
•Greek astronomy
•Celestial Sphere
•Astrolabe and sundials
•Mathematics
•Zero and Arabic numbers
•Greek geometry
•Algebra, algorithm
•Spherical trigonometry
• Dark Ages in Europe
• Built on the best of
East and West
• Reintroduced texts
and knowledge of
Greeks and Romans
• Ptolemy’s “Almagest”
• Focus: Marking time
– Calendar, lunar month
– Prayer times
– Direction to Mecca
Library Hagia Sophia
The End
One Book: Koran
References and Photo Credits
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Istanbul Topkapi Palace, Sundial of the Month, Dec 2005” Joel Robic
http://pagesperso-orange.fr/cadrans.solaires/cadrans/cadran-istanbul-topkapi.html
“Principle and Use of Ottoman Sundials” Atilla Bir
http://muslimheritage.com/topics/default.cfm?ArticleID=942
“OSMANLILARDA GÜNEŞ SAATLERİ” Prof. Dr. Atilla Bir
www.akat.org/ast_tarihinden/osmanli_zamani/gunes_saati/
“Sundials in Medieval Islamic Science and Civilization” Len Berggren, NASS, 8-2 June 2001
“Astronomy in the Service of Islam”, David A. King, Variorum 1983.
“In Synchrony with the Heavens” V1 “The Call of the Muezzin” D. A. King, Brill 2001
“A Uniform Method to Compute Flat Sundials” Fer de Vries: ZW 2000
http://www.de-zonnewijzerkring.nl/eng/index-vlakke-zonw.htm
“Error Analysis of the Horizontal Sundial – IX Dial Rotation” T. J. Lauroesch and J. R. Edinger, Jr. ,
NASS Compendium 4-4 Dec 1997
Les cadrans solaires de monde de l’Islam (Sundials in the Islamic World), Chapter X, Les cadrans
solaires, histoire, théorie,practique” René Rohr, Oberlin, 1986 (This section is In European editions
not North American editions in English, U o f T 1970 or Dover 1996)
The Meridian of Ibn Al Shatir –Umayyad Mosque in Damascus” Gianni Ferrari, unpublished
personal communication
“Error Analysis of the Horizontal Sundial – IX Dial Rotation” T. J. Lauroesch and J. R. Edinger, Jr. ,
NASS Compendium 4-4 Dec 1997
Slide 1: Atilla Bir “Principle and Use of Ottoman Sundials”
Slide 2,13,14,16: Alain Ferreira, Joel Robic, “Istanbul Topkapi Palace”
Slide 3,34,35, 51,52, 54, 56: Don Snyder
Slide 32: Ian Adams, Missouri Botanical Garden,
Slide 33, 57: Laila Wessel, Missouri Botanical Garden