2021 Conference - Philadelphia

Details

Published: 16 August 2021

Hits: 1971

The North American Sundial Society, after by-passing the 2020 Conference due to Covid restrictions, held the 26th annual meeting from August 5th - 8th at the Hilton Garden Inn, Center City, Philadelphia. The venue was similar to past conferences: Thursday night social and door prizes for attendees, Friday a bus tour of 11 sundials in the Philadelphia area, Saturday sundial presentations and annual dinner, finishing on Sunday with more sundial presentations and the annual general meeting (AGM).The dial tour took us walking through Philadelphia parks and arboratums and visits to University of Pennsylvania, Swarthmore College, and Haverford College.

At Swarthmore we saw the modern vertical declining dial on Kohlberg Hall, designed by Martin Cowan. Frederick Orthlieb, professor and chair of the Dept of Engineering at Swarthmore "had a part in locating the bent-plate gnomon so as to give correct indications on the vertical wall. As installed, the gnomon's indicating edge (which lies on a Polar Axis) casts quite a short shadow in Autumn and Winter and requires some observing skill to make a close estimate of indicated time, but in Spring and Summer the longer shadow moves over the granite hour marks very plainly."

For the annual group photo attendees gathered around the "Point Where Things Change", a N-S meridian dial commissioned in 2001 by the Redevelopment Authority of the City of Philadelphia and designed by Michael Grothusen. The dial is on the grounds of Tasepoint Corporate Headquarters.

From Left to Right: Bill Gottesman, Joyce Robinson, Pam Morris, David Robinson, Bob Kellogg, George Wilson, Jack Aubert, Will Grant, Betsy Wilson, Jim Holland, Bill Thibault, Art Paque, Tish Grant, Fred Sawyer, Philomena Sawyer, Phyllis Montgomery, Jeff Kretsch , Mark Montgomery, Marvin Taylor, Zoon Nguyen, Kate Aubert, Pat O'Hearn, Roger Dignard, Paul Ulbrich.

Attachments:

2021_NASS_Conference_Philadelphia.pdf

[ ]

0 kB

3D Printing Tutorials

Details

Published: 24 November 2019

Hits: 6316

Look for the new menu tab:3D Printing Tips.  Starting this December (2019) NASS begins a series of tutorials using OpenSCAD and other software for designing and printing 3D objects.  As you might guess, we'll focus on creating sundials and other shadow casting objects.  Download your copy of OpenSCAD at http://www.openscad.org and join our tutorials.  If you want even more detail on 3D sundials, join NASS and receive The Compendium with Bill Gottesman, Steve Lelievre, Bob Kellogg and others writing in the regular column "3D Design and Printing Sundials."

Seattle Sundial Tribute

Details

Published: 09 December 2014

Hits: 16522

Professor Woody Sullivan's Reflection Dial [photo - NASS Conference 2011]

Professor Woody Sullivan of the University of Washington in Seattle, whose long time motto has been "Seattle, sundial capital of North America", received a tribute from local television station King5 for sundials that he has designed or brought to light around Seattle. His pride and joy is his ceiling reflection dial [photo at left] As related by Joan Kinsey from King5 news, "It took Sullivan and an artist three years to chart hundreds of reflected dots across the top of Sullivan's remodeled garage..." The celestial view includes hour lines, solar declination lines of the equinox and the soltices, and a variety of transit dots that represent special dates and times to the Sullivan family.

Sullivan, a professional astronomer, has helped design a number of Seattle dials. As Joan Kinsey notes, "His first one [a declining vertical dial] went up in 1994 on the side of the astronomy building at the university ...The huge wall sundial ignited Sullivan's passion to make more and research the ones that already exist in town." Woody has created a Sundial Trail of prominent Seattle dials ranging from several vertical dials increasing the educational value at local schools to a large Shepard's dial and an occulus gnomonic dial.

Of course being Seattle, Woody scribed an appropriate sundial motto, "I thrive in the sun, Can't work in the rain. So, if I'm beclouded, please come back again. "

Read about it at: king5 news

Pleistocene Sunburst Pocket-Art Unearthed

Details

Published: 28 March 2020

Hits: 4947

Photo Credit: Andrew Thompson

Archaeologists have found two miniature stone engravings in a cave on the island of Sulawesi in Indonesia. One plaquette appears to be a sunburst, the other an ibex like animal, the anoa. These pocket-sized carvings dating back between 14,000 and 26,000 years. Elsewhere in Sulawesi the oldest cave art dating to 44,000 years ago was recently discovered, dispelling the Euro-centric notion of Pleistocene art.

Examining the incisions cut into the ancient flowstone, the Sunburst hexegon outline was carved starting in the photo from upper left, with continuing connecting lines done clockwise. Then the 7 rays were added. Small traces of a red mineral (perhaps red ochre pigment) exist in some of the sunburst cuts, possibly indicating that the sun was enhanced in a beautiful red color. Before this discovery the oldest known depiction of the sun was from the Nebra sky disk found in Germany and fabricated of metal 3,600 years ago, rivaling Pharaoh Akenaten who built a whole city to the glory of the sun (Aten) 3,365 years ago. These are recent times compared to the sunburst.

The archaeology team was lead by Michelle C. Langley of the Australian Research Centre for Human Evolution, Griffith University, with associates at Arkeologi Nasional (ARKENAS), Jakarta, Balai Arkeologi Sulawesi Selatan and Balai Pelestarian Cagar Budaya in Makassar. They report in Nature Human Behaviour "... the discovery of two small stone ‘plaquettes’ incised with figurative imagery dating to 26–14 ka from Leang Bulu Bettue, Sulawesi. [The pocket-art was discovered in a cave and rockshelter complex of Leang Bulu Bettue (4° 59' 31.18" S, 119° 40' 5.53" E) situated at the foot of a limestone tower in the Maros-Pangkep karst area.] These new findings, together with the recent discovery of rock art dating to at least 40 ka in this same region, overturns the long-held belief that the first H. sapiens of Southeast Asia–Australasia did not create sophisticated art and further cements the importance of this behaviour for our species’ ability to overcome environmental and social challenges."

The artefacts reported here are currently curated at the Australian Research Centre for Human Evolution, Griffith University, Nathan, Australia. They will return to Indonesia at the conclusion of the project where they will be given accession numbers and be curated in Makassar by Balai Arkeologi Sulawesi Selatan.

Read more at:

Hemicyclium Sundial Discovered in Turkey

Details

Published: 21 March 2020

Hits: 7866

Several years ago in 2017 archaeologists found a rare hemicyclium sundial. Now another hemicyclium in excellent condition has been unearthed in Turkey's city of Denizli. Celal Şimşek, chief archaeologist at Denizli's Pamukkale University, calls it "unique". A better word is rare. Less than a hundred examples of this type of Hellenistic sundial have survived. It was found in the ancient city of Laodicea about 370 miles south of Istanbul. The sundial seems to have come from the archaeological site of one of the temples. As reported in the Daily Sabah, "Among the rare, largely preserved buildings in the city are the largest ancient stadium in Turkey, a theater and a sacred agora." The hemicyclium of pink marble has an outer edge decorated in foliage while the interior hemisphere has the traditional Greek names of the seasons. Hour lines deliniate the time. Almacantor lines show the solstices and a great circle marks the equinox. In AA Photo of the sundial at right, a needle gnomon has been restored to show how the sundial casts a shadow. Time and season are read at the gnomon shadow's tip.

Read more at: https://www.dailysabah.com/life/history/2000-year-old-sundial-unearthed-in-southern-turkeys-denizli

ADDENDUM FROM SUNDIAL DIGEST - 10 April 2020

I would like to add two arguments to the questions [of the sundial's age] under discussion:

1. Prof. Şimşek said: “On the North Parados passage in the Western Theater, which dates back to the Hellenistic Era, in the ancient city we have found a spherical sundial facing south, which we believe to be 2,020 years old.

This is a kind of conclusion which does not help by dating the dial. A comparison with similar specimens reveals that it was probably done around 200 – 400 CE.

2.  “Inscribed on the dial are the Greek word ‘Ksimerini’, or winter on the upper part; ‘Isimerini’, or solstice, which denotes the equality of day and night in the middle; and ‘Terini’, or summer in the bottom.”

I read (ΤΡΟΠH) ΧΕ(Ι)ΜΕΡΙΝH / IΣΗΜΕΡΙΝH / (ΤΡΟΠH) ΘΕΡΙΝH.

These are the names of the solstices and the equinoxes. What is conspicuous is the missing of I in χειμερινή (it should be written with diacritic signs). That is another strong argument that it was done in the Roman era.

With best wishes

Karlheinz Schaldach

Sundial Discovered in Madaba Map Mosaic

Details

Published: 22 December 2019

Hits: 5954

We've reported on ancient mosaics from Turkey showing sundials (Antioch Mosaic Sundial - 2016).  Now from the Ministry of Sciences and Higher Education in Poland ( Archaeology News - Ancient Sundial and Science in Poland ) another ancient mosaic sundial has been discovered:

Sundial in the Madaba Map, a great mosaic located in Jordan. The sundial is located next to the gate on the left. Credit Wikipedia/public domain.

Professor Marek T. Olszewski from the University of Warsaw was re-examining a number of mosaics dating back to the 2nd century AD when he made his startling discovery.

One of the mosaics from the 6th century AD which was discovered by the Gate of Damascus in Jerusalem, Olszewski noticed that between a richly dressed women, a mysterious object is visible, which scientists at the beginning of the 20th century described as an oil lamp or column.

Olszewski said: ”After careful analysis and comparison with a sundial discovered during excavations, I came to the conclusion that this mosaic and other ones similar to it depict sundials....

Another sundial "tracked" by the Polish researcher is located in a wall mosaic in Santa Cecilia in Trastevere church in Rome. This mosaic was created during the time of Pope Paschal I (817-824).

Prof. Olszewski also noticed a previously unknown sundial in the Madaba Map - a huge floor mosaic, which is currently stored in the church of St. George in Madaba, Jordan. It shows a map of the Middle East from the Byzantine period. This is the oldest cartographic depiction of the Holy Land, including Jerusalem and dates back to the 6th century AD.

Yet another depiction of a sundial comes from Tarsus (Mersin) in Turkey, where a figural mosaic (ca. 2nd-3rd century AD) shows a sundial on a column and a crow sitting on it. A man tries to scare off the bird by throwing a pouch at it (crow was a symbol of a bad omen).

Professor Olszewski has now discovered eight previously unknown sundials in the designs, taking the total number known to 15.

Time and Cosmos

Details

Published: 06 December 2016

Hits: 6995

Horizontal Gnomonic Dial (Inv. 3075) by permission Museo Archeologico Nazionale di Napoli

Statuette of Atlas Bearing a Hemispherical Sundial by permission Sir John Soane's Museum, London

The Institute for the Study of the Ancient World  (15 East 84th Street in New York) is hosting an exhibition "Time and Cosmos in Greco-Roman Antiquity" open to the public from now until April 23, 2017.  From their on-line invitation, "This exhibition aims to explore the ways that time was organized and kept track of in the Greco-Roman world, and how it was conceived in relation to the Cosmos. The objects displayed include artifacts illustrating the technology of ancient time-reckoning and the perception, visualization, and social role of time and cosmos..."  This is exemplified by a wonderful horizontal gnomonic sundial using a vertical gnomon shown at left.  It was found at Pompeii around 1865 and became part of the Museo Archeologico Nazionale di Napoli in 1867. "Despite the fact that it was found in Italy, the inscriptions on it are in Greek, perfhaps reflecting the status of Greek as the langauage of science in antiquity. The summer and winter tropics (solstices), equinox, and seasons are reasonably declined.  The hour lines however reflect temporal hours rather than the hour angles we would draw  todayl.

Read more: Time and Cosmos

Athens Tower of Winds Opens to Public

Details

Published: 27 August 2016

Hits: 14242

In the old Roman Agora on the slope of Athen's ancient Acropolis hill is the Tower ofWinds.  Today, completing two years of restoration, the interior was re-opened to the public this summer in August, 2016. The Tower had been closed for the last 200 years.  The story of the Tower starts in the first century, BCE, probably during the reign of Julius Caesar.

The Tower was designed by Andronikos Kyrrhestos (Andronicus of Cyrrhus), an astronomer and maker of celestial instruments. Andronicus constructed a white marble sundial for the sanctuary of Poseidon and Amphitrite on the island of Tinos.  The sundial becamse so famous that Andronicus was invited to Athens where he erected the magnificent 14 meter Tower called the Aerides (the Winds) . It was built on the eastern side of the Roman Agora in Athens and meant to have utilitarian value. "No one knows who funded its lavish construction - the octagonal monument is made almost entirely of Pentelic marble, the same used for the Parthenon and rarely found in buildings other than temples," said Stelios Daskalakis, head conservator.

Atop of the octogon tower now rests the fully-preserved roof made of 24 marble slabs, resting on a Corinthian capital. Once a bronze statue of Trition, the god of the sea, was set on the roof to turn in the wind as a weather indicator.  By night, water flowed through a hydro-mechanical system designed by Andronicus from a cylinder inside the Tower.  The water level lead to an exterior indicator creating a night time clock or  clepsydra. During the day the Tower was a public time teller with eight sundials.

Attachments:

NASS_Theodossiou_Tower_of_Winds.pdf

[ ]

960 kB

Read more: Athens Tower of Winds Opens to Public