Presentation is loading. Please wait.

Presentation is loading. Please wait.

Ottoman Sundials Roger Bailey NASS, St Louis, 2008.

Similar presentations

Presentation on theme: "Ottoman Sundials Roger Bailey NASS, St Louis, 2008."— Presentation transcript:

1 Ottoman Sundials Roger Bailey NASS, St Louis, 2008

2 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 ( ) Renovated in 1794 by Seyyid Abdullah

3 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

4 15 th 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 ( ) Ottoman? Mehmet II (the Conqueror)

5 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


7 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

8 Battle of Lepanto 1571 Ottoman navy defeated by Don Juan and combined fleet of Holy League

9 Mehmet II Sultan Emperor, warrior, scholar Built Istanbul: Topkapi Palace Converted Hagia Sophia to a mosque

10 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

11 Hagia Sophia: Istanbul Byzantine Cathedral: Divine Wisdom Roman Emperor Justinian s Sultans Mosque, now museum

12 Hagia Sophia: Istanbul

13 Topkapi Palace, Istanbul Build by Mehmet II on ruins of Byzantine palaces Palace, harem, government center, gardens Ottoman sundial in Third Garden

14 Topkapi Ottoman Sundial

15 Topkapi Palace Ottoman Sundial

16 Ezanic Hours

17 Asr Italian Babylonian

18 Polar Gnomon Support Hour Lines:Angles Hour Scale: Based on Noon as 6 oclock. Ottoman Turk Numbers Outer Scale: Polar Sundial Tan (Hour Angle) = Tan (time angle) x Sin (latitude)

19 Ibn al-Shatir s Sundial Damascus Umayyad Mosque 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 Replica in Damascus Museum

20 Ezanic Hours At sunset, day ends 12 and starts at 0 Vertical Peg Gnomon Tip of shadow tells time Date Lines: Shadow path On solstices and equinox Summer 21 June Winter 21 June Ezanic Hours: Sunset 12 off scale to east (left) 24 in Italian Hours Babylonian Hours: Sunrise 12 off scale to west(right). Mirror image

21 Moslem Prayer Times Asr starts when shadow length is noon shadow + gnomon height Asr ends when shadow length is noon shadow + twice gnomon height

22 Ibn al-Shatir Sundial

23 Kairouan, Tunisia Great Mosque

24 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

25 Kairouan Mosque Sundial

26 Veni Camii Istanbul: New Mosque Yeni Camii

27 Vertical Declining Sundials

28 New Mosque Yeni Camii 2 Local hours 20 Polar Gnomon bent horizontal (Moslem style)

29 New Mosque Yeni Camii 1 -Local hours 20 -Ezanic hours -Asr 1 & 2 -Zhur? -Declination

30 Overlay confirms declination lines, equinoctial and Asr Prayer line (N + G). Zuhr Prayer line and parallel curved time lines are different New Mosque Yeni Camii 3 Islamic sundial Prayer times Hours? 20

31 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

32 Missouri Botanical Garden

33 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

34 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


36 Differences: Topkapi and Missouri Goal: Comprehension not confusion Noon is 12 not 6 on polar dial Arabic not Ottoman numbers Fewer Lines –Time division: not –Hours & Half hours (30 min), not 20 minutes Prefered view: from South Latitude 41 vs 38.6

37 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

38 Polar Sundial Design 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

39 Hours from Sunrise Ezanic Sundial : Sunrise North South West East Sunrise 12 &0 off scale to West (left), 24 in Babylonian Hours Babylonian Hours are the reverse of Italian Peg Gnomon Winter AM 2 hours after sunrise

40 Ezanic Sundial : Sunset Date Lines: Shadow path On solstices and equinox Summer 21 June Winter 21 December Equinox North South West East Ezanic Hours: Sunset 12 off scale to east (right) 24 in Italian Hours Hours from previous Sunset Peg Gnomon

41 Ezanic Timelines Simplified 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 West East Equinox Red: Italian Sunset Blue: Babylonian

42 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

43 Daily Prayer Times Midnight Midday Sunrise Sunset Daybreak Nightfall Monastic Prime Matins Triece Sext Nones Vespers Compline zuhr asr maghrib isha fajr Moslem duha

44 Moslem Prayer Times Gnomon Noon Zuhr Defined by altitude of sun determined by shadow lengths Zuhr = Noon + ¼ gnomon height Asr = Noon + gnomon height to Noon + 2 gnomon heights Asr

45 Moslem Prayer Timelines Istanbul: Latitude 41º N Horizontal with Vertical Gnomon Zon 2000

46 Qibla: Direction to Pray 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


48 Gnomons: Polar & Peg

49 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

50 Merge DXF Files End of First DXF * VERTEX 8 L_A SEQEND 8 L_A 0 ENDSEC 0 EOF Start of Second DXF 0 SECTION 2 ENTITIES 0 LINE 8 L_$ * 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


52 Construction: Abraham Molher 11 March – Marble 1 April – Carving 7 April – Gnomons 9 May – Installation 16 May -Dedication


54 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

55 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 :02 Clock to Solar 10:25 Observed Error 8 min Predicted Error 15 min


57 Reorientation Design Dial oriented to polar axis Stone oriented to Garden axis, 7.5º east Outer dial scale oriented with stone

58 Reorientation Design Dial oriented to polar axis Stone oriented to Garden axis, 7.5º east Outer dial scale oriented with stone

59 Proud Artisans Abraham Mohler Sculptor Roger Bailey Designer

60 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

61 Islamic Culture and Science Astronomy and Mathematics Dark Ages in Europe Built on the best of East and West Reintroduced texts and knowledge of Greeks and Romans Ptolemys Almagest Focus: Marking time –Calendar, lunar month –Prayer times –Direction to Mecca 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

62 Library Hagia Sophia One Book: Koran The End

63 References and Photo Credits Istanbul Topkapi Palace, Sundial of the Month, Dec 2005 Joel Robic Principle and Use of Ottoman Sundials Atilla Bir OSMANLILARDA GÜNEŞ SAATLERİ Prof. Dr. Atilla Bir Sundials in Medieval Islamic Science and Civilization Len Berggren, NASS, 8-2 June 2001 Astronomy in the Service of Islam, David A. King, Variorum 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 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 lIslam (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

Download ppt "Ottoman Sundials Roger Bailey NASS, St Louis, 2008."

Similar presentations

Ads by Google