In August 2017 the North American Sundial Society held its annual conference in St. Louis Missouri with a series of well attended talks on the mathematics of sundials, software tools to design sundials, and even videos on YouTube that are about sundials. NASS participants visited local astronomical sites of interest, including the War Memorial Dial in Forest Park. Don Snyder worked with Perry County and Perryville, a town on the eclipse path, to creat a new sundial for the courthouse gardens. Local craftspeople created the dial following Don's design. It, as other significant dials, is in the NASS Sundial Registry available on the web. At the Missouri Botanical Garden attendees saw the Schmoyer Sundial with its analemma shaped gnomon to tell civil time. It was made by Bill Gottesman and donated to the Garden by Don Synder and Bill. Also at the Botanical Garden is the Ottoman dial designed by Roger Bailey, following the design of the horizontal dial at Topkapi Palace in Istanbul. A presentation from Bill Iseminger on the Cahokia Woodhenge discussed the astronomical alignments such as solstice sunrise and sunset. Wood Henge was on the sundial tour itinerary, but due to heavy traffic, was excluded to reach the eclipse viewing site on time (the sun and moon had their schedules that were not subject to change).

The highlight was a visit to Jefferson Barracks to watch the total solar eclipse on August 21, 2019. All participants were given special safe viewing glasses to protect their eyes before and after totality. With cooperating weather, the eclipse was viewed with devices ranging from a pinhole camera obscura to telescopes with solar filters. A truly spectacular event. Bill Gottesman demonstratee his eclipse "sundial" that used the orientation of the eclipsed sun's cusp orientation as an indicator of time.

Download the Retrospective: 2017_NASS_Conference_St.Louis.pdf

(Left) NASS Eclipse Watchers; (Right) Pinhole images of cresent sun

Details

Last Updated: 16 August 2021

Hits: 9722

One of Bowdoin's Vertical DialsThe NASS Conference in Portland, ME began with a sundial tour, highlighting the Children's Museum of Maine and the large Camera Obscura.  From there, attendees toured a number of sundials including armillary spheres, vertical and horizontal dials, including the Bowdoin College Vertical Dials and Osher Map Library that showed maps with the figure 8 analemma, filling the void in the Pacific Ocean next to comments like "There be dragons here".  Osher Map Library During the conference a variety of sundials were the topic of presentations.  Bob Kellogg presented his digital sundial while Jame Stegenga showed his concrete sundial for the courtyard of a courthouse in Brazil.  Patrick O'Hearn showed his handiwork of making wood sundials and Mark Montgomery presented his handiwork of creating a mosaic spherical sundial. Barry Duell talked of his experiment to determine when the moon would shine through his window onto his pillow.  By measuring the geometry of the window and bed, he determined the range of acceptable lunar altitude and azimuth.  From there, using an ephemeris, he could predict date and time the moon would shine on his pillow as he drifted off to sleep.  Other presentations included the anatomy of the astrolabe by Tom Wujec.

Download the Retrospective: 2016_NASS_Conference_Portland.pdf

(left) Kellogg's Digital Dial & (right) Stegenga's Brazil Dial

 

Details

Last Updated: 19 June 2026

Hits: 11564

Ellipsoidal Gnomon Sundial at Stanley ParkThe 2015 NASS Sundial Conference was held in Victoria, B.C.  Roger Bailey organized the conference and provided a sundial tour in Victoria, stopping at the BC Legislature Rose Garden dial, the St. Ann's Academy dial, Christ Church Cathedral vertical dial, the BC Government House totem sundial, and more, including a visit out to the Dominion Astrophysical Observatory to see the 1.8 meter telescope.

Steve Luecking discussed spherical and elliptical gnomons where tangent points are dropped to a circle circumscribing the ellipse and hour lines are then drawn as tangents from the points on the circle.  Steve used this technique to design a sundial using an elliptical gnomon with symbolic native art for Victoria. (Illustration at right)

Len Berggren described the design and building of a sundial that can show both solar and mean time, done with a $1000 grant from NASS.  Presentations included John Schilke discussing the Heliotrope and Heliograph.  Barry Duell outlined the history of a sundial at Willamette University donated by the Class of 1916.  The dial was dedicated to Prof. Matthews and engraved with his motto of "Sagacity, Audacity, Holiness, Chairty."

Prof. Woody Sullivan described 3 new dials.  The first two, an Oculus table and a Solar Hour Benches are at the San Francisco Exploratorium.  The third dial at the Very Large Array Radio Telescope in New Mexico is the world's first and only sundial made from one of the original radio telescopes.  It was constructed in memory of Prof. Ron Bracewell of Stanford Univ. a pioneer in radio astronomy.

Jackie Jones, Doug Bateman, Sasch Stephens, Fred Sawyer, and Mark Montgomery presented a wide range of topics from reflecting dials, elliptical dials and moon dials, to ancient Egyptian shadow clocks.  Bob Kellogg, unable to attend, sent along a video on a new digital gnomon sundial, while Frank King and Steve Luecking discussed optical geometries and illusions.

Download the Retrospective: 2015_NASS_Conference_Victoria.pdf

Details

Last Updated: 16 August 2021

Hits: 10482

Founding Fathers George Washington and Dial at Mount VernonIn August, 2014, the North American Sundial Society had a terrific conference in Indianapolis, Indiana, discussing sundial topics from the sundials of Our Founding Fathers where Fred Sawyer talked about the sundials and stories of George Washington, Benjamin Franklin, and Thomas Jefferson.

Ai KhanumDial Peculiarities Discussed by Jack AubertAnother highlight was Jack Aubert's talk on the mysteries of an ancient Greek sundial found at Ai Khanum in the northern of Afghanistan and computing the hour lines.  Who built this dial more than 2000 years ago and what kind of mathematics did they use?

Peggy Gunnerson described the evolution of a modern sundial parallelpipeds sculpture, creating an artistic and unusal east-west sundial.  And Stephen Lueking presented a series of modern sundial designs for DePaul University.  These were just some of the presentations.  Subscribe to the digital edition of The Compendium from NASS and receive them all.  The annual Sawyer Dialing Prize went to Robert Kellogg for NASS outreach and the invention of a digital sundial.  Read more about the presentations and the tour of Indianapolis by downloading the attachment below.

(left) Parallelpiped Dial by Peggy Gunnerson and (right) Point Dial for DePaul University designed by Stephen Luecking

Hosting 46 people, the conference was coordinated by George and Betsy Wilson and Mark an Phyllis Montgomery.  During the Friday Sundial tour NASS was welcomed by Eagle Elementary School, the senior high ability class and their teachers.  All gathered in the school's courtyard to show a large horizontal sundial, dedicate3d as a memorial to a former teacher, Linda Eads.  Download the Retrospective: 2014_NASS_Conference_Indianapolis.pdf

NASS Attendees at Eagle HighSchool Memorial Sundial

Details

Last Updated: 16 August 2021

Hits: 14404