It's coming - The 26th Annual North American Sundial Conference. This year from Thursday Aug 6 unti9l Sunday Aug 9th we'll be in Philadelphia within walking distance of Indepencence Hall, The Liberty Bell, The Benjamin Franklin Museum and much more. Make your reservation at the Hilton Garden Inn, Philadelphia Center, 1100 Arch St. Details are in the attached flier.
Each year North American dialists gather to share presentations and displays of sundial projects. Why come? What people have said: "First, and foremost, I have fun! To talk about and cover my ideas on this strange area of imagination with like-minded folks is very rewarding and what a congress of interesting and kind minds! Second, there are real dials to see, admire, and analyze [during our Friday field trip] - all incised in a convenient and comparable way. And these are not the sites usually touted by the locals as meaningful. Finally, there is a local stamp of author on things that are not totally abstract. Where else can one see mathematical ideas?"
Combine your interest in sundials with an immersion in American history and join us to meet old friends, make new acquaintences, and gain gnomonic insights. Another attendee said "The presentations are a chance to brush up on my fading math abilities, inspire the possibilities of new dial creations, and learn odd quirks of history. I always leave the conference eager to start my next dialing project. The bus tour of local dials provides both beautiful dials, many in garden settings, and discusses the foibles of implementing a dial design to remain an accurate timekeeper."
Until May 1st the registration fee for full participation is 325 USD. After May 1st it will cost 350 USD. Sign up now.
 Register_Philadelphia_Aug_2020.pdf | [ ] | 216 kB |
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.
From the Harvard Gazette - Dec 9, 2019 : "Since 1672 Harvard University has been acquiring scientific instruments for teaching and research. In 1948 the Collection of Historical Scientific Instruments was established...[and has] grown to more than 20,000 objects making it one of the three largest university collections of its kind in the world"
As an illustration of the collection is a photograph of ivory pocket sundials shown here, made in Nuremberg, Germany between 1575 and 1645. These elegant diptych sundials represented the 16th and 17th century equivalent of pocket watches, especially for wealthy traveling merchants to keep track of time. "Harvard has the largest collection of sundials in North America, a gift of David P. Wheatland, Class of 1922."
As described by Dr. Sara Schechner in Time of Our Lives - Sundials of the Adler Planetarium who is the David P. Wheatland Curator of Historical Instruments at Harvard describes the diptych as "fashioned from ivory, gilt brass, carved wood, and wood covered by printed paper. The materials offer hints on the social status of their owners. So too do common and novel accessories found on the instruments. A directory of cities and their latitudes suggests an owner who traveled... The association is stronger when the diptych combines a gazetteer with particular sundials that found the time according to the sundry conventions of England, France, Germany, and Italy. A merchant crossing a border would have needed to know how to set up an appointment with his clients. How many hours would there be to transact business or to journey along the road? Calendrical devices on the diptych showed him the length of the day and night throughout the year...[and] the diptych's lunar volvelle gave ...the moon's phase. It also assisted the owner in finding the time by moonlight...[And] a diptych with a magnetic compass [allowed proper and immediate orienting the sundial]."
Read more at: https://news.harvard.edu/gazette/story/2019/12/collection-of-historical-scientific-instruments-continues-to-amaze/
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."
Whether it be Delhi or Las Vegas, artist Daku brings shadows to life, creating words that slowing change their shape but never lose their meaning through the course of the day. As reported by mymodernmet.com, "As part of the St.Art festival, which curates public art in Delhi’s Lodhi district, Daku’s carefully realized [shadow] installation demonstrates the power of words. The artist, whose name means 'bandit' in Hindi, had been thinking about executing this project for several years when finally given the opportunity by the festival." The anonymous artist Daku told CNN, “I had to decide the size of the letters, the length of the pieces, and the angle I could place them in so pedestrians could easily see it.” mymodernmet.com concluded "The artist carefully selected which words to include—balance, order, reflection, future, seasons, space—each a reflection on movement, time, and change. Reaching its apex at mid-day, the letters slowly blur and dissolve, put to rest each evening before beginning anew."
The making of shadow writing in Las Vegas by Daku
Daku's cut-out words on the south facing walls of buildings is a clever implementation of sundial and involves a lot of subtle mathematics. Daku's lettering is placed on the wall horizontal to the ground, usually with very little change in the scale of the lettering. Mathematically the noonday lettering on the wall is lengthened by the tangent of the latitude plus solar declination. But the visible size of the lettering is foreshortened by the cosine of the upward look angle of the pedestrian on the ground.
Read more at: Daku's installation in Las Vegas and Daku's installation in Delhi
On the State Capitol grounds in Richmond Virginia the Women's Monument was unveiled on Oct 14, 2019 as part of celebrating the 100th anniversary of the 19th amendment that gave women the right to vote. The Women's Monument, commissioned by the Virginia Department of General Services, negotiated two contracts with local artists on behalf of the Virginia Women's Monument Commission who has raised more the $3.7 million for this monument. The result is a large circular plaza with 7 life sized bronze statues of influential Virginia women during the last 400years. The monument will eventually feature 5 more life-size bronze statues. The statues are backed by a glass wall with the inscribed names of 230 infuential Virginia women on the Wall of Honor.. The monument is a work in progress and intends to not only complete the last 5 statues, but add other women's names to the Wall of Honor.
In the center of the plaza on a wide circular pedestal is a bronze sundial. In addition to the normal dial furniture of compass rose inscriptions, site latitude & longitude, and a chapter ring with the hours from 5am to 7pm there is additional information: points of locations in Virginia are shown around the dial in the outer chapter ring. Each location is listed by name, azimuth, and distance from the Capitol site.
With all the work to create this magnificent monument to women there is a monumental nit pick. At azimuth 354 deg and 108 miles away is "Loudon". Locals immediatedly spotted the typo for Loudoun County, which according to the official county history recorded: "In 1757, by act of the Virginia House of Burgesses, Fairfax County was divided. The western portion was named Loudoun for John Campbell, the fourth earl of Loudoun, a Scottish nobleman who served as commander-in-chief for all British armed forces in North America and titular governor of Virginia from 1756 to 1759."
In spite of the typo, the dial is an impressive work of art approximate one meter in diameter.
Photo Credit: Sara Hunt, Virginia Capitol and AA Communications
In October 1999 the cities of Lafayette and West Lafayette, IN dedicated a modern looking 8-foot high equatorial dial in honor of the coming millennium. The dial was designed and built by David Aho with a stainless steel equatorial band 60 inches in diameter. The equatorial band has a brass inlay showing the hour marks with Roman numerals. The dial still looking clean and modern located on the John T. Myers Pedestrian Bridge and has a dedication plaque Oct 22,1999. As reported by wlfi.com news, it was one of the first public art installations in the community. Now the dial is celebrated as paart of October's Community Planning Month. You can see photos of the dial on the NASS registry at http://www.sundials.org/index.php/sundial-registry/onedial/376.html or you can watch the Wlfi.com video at: https://www.wlfi.com/content/news/October-is-now-known-as-Community-Planning-Month-in-Greater-Lafayette-562876071.html
In downtown Joplin, MO, John Hadsall of the Globe digital edition began probing into the sundial on the face of Ron Jones's Commerce Building at 113 West 3rd St. Hadsall says, "I’ve been enchanted with this sundial ever since I noticed it during a lunch-break walk. I’ve written before about how I hoof it downtown and find all sorts of treasures under our noses, from the amazing front porches in the North Heights Neighborhood to the brick sidewalks that remain throughout that neighborhood, Murphysburg and other downtown residential areas."
"The sundial is believed to have always been a part of the more than 100-year-old-building. Originally built in 1904 for a machinery company, it was remodeled into a bus station in 1937." And over the years the building was abandon, finally being purchased by Jones and his business partner Ivan McElwee. John proceeded to see if the dial told accurate time, taking a photo of the dial and its shadow "at about 1:05 pm on Thursday [18 July 2019], I took a picture of the sundial at 111 W. Third St... It appeared to be a little behind: The shadow of the gnomon was still crawling toward dead center of the 12."
John gives several possibilities of the dial's time inaccuracy, but the truth is far more interesting. The founders of Joplin in 1873 used magnetic north to lay out the street grid. The recessing of the sundial in the wall aligns the dial to true north south. A very close look at the dial construction shows that the afternoon hour lines converge on the eastern edge of the toe of the gnomon. That is, this sundial was designed for the thick one inch gnomon where morning hour lines converge on one side of the gnomon and afternoon hour lines on the other To read the time, one needs to drop lines from the left and right gnomon edges straight down creating a split noon. For the morning, read the western shadow edge with reference to the west gnomon line, giving a shadow time of about 11:41 solar time.
The Joplin dial is at 37° 5.0' N, 94° 30.8' W, about 4.5° west of the central time meridian at 90° W. That translates to 18m early. That is, when the sun is over the central time meridian, it will take another 18m before noon occurs in Joplin. We also need to include the sun's Equation of Time, that annual variability between solar and civil time due to the earth's slightly eccentric orbit and 23.4° tilt of its axis. Calculations of the EOT are provided by the British Sundial Society and others, showing that on July 18th the sundial was slow (early to clock time) by just a bit more than 6m, giving a total difference between sun and civil time of 24 minutes. With above photo taken at 1:05pm central daylight time, we subtract 1h 24m to get sundial time of 11:41am.
So now you know that this century old sundial at 111 W Third Street still keeps accurate solar time, and with a little math, you can set your watch to the minute! You can hear an edited version of John's blog with history and his not so precise conclusions about the sundial here:
For a full version of John Hadsall's podcast "In Case You Missed It" go to: https://www.joplinglobe.com/multimedia/podcast-in-case-you-missed-it-sundial-building/audio_95587b74-ab7c-11e9-b4e8-bfc13b97fe5b.html
and you can read John's blog at: https://www.joplinglobe.com/news/lifestyles/joe-hadsall-downtown-sundial-still-working-as-intended/article_6cf74006-963d-5439-83cc-e6bdafd85dd3.html