Sundials - World's Oldest Clocks

North American Sundial Society

Pittsburgh SundialNASS will hold this year's annual conference Thrs 16 Aug - Sun 19 Aug in Pittsburgh, Pennsylvania.  The conference will be held near the famed University of Pittsburgh campus with its Cathedral of Learning.  The conference will be held at the Hilton Garden Inn, Pittsburgh University Place 3454 Forbes Avenue in Pittsburgh.

NASS has a discount rate for the conference at $119/night (plus tax).  This rate will also apply 4 days before and 4 days after the conference, if rooms are available.  You can call the Hotel at 412-683-2040 for reservations or visit the Hilton webpage specifically set up for NASS reservations at: The hotel is about 20 miles from Pittsburgh International Airport with SuperShuttle transportation to the hotel at  Use the GUENB to receive a discount round-trip ticket. 

Please let us know at This email address is being protected from spambots. You need JavaScript enabled to view it. when you've made a reservation at the Hilton so that we can adjust the number of allocated rooms if appropriate.  We want to be sure that we have room for everyone during this peak season.  Book early.

If you would like to present a talk at the NASS conference or do an informal 5-10 presentation on your favorite dialing project, please contact This email address is being protected from spambots. You need JavaScript enabled to view it.  If you have sundials, photos, books, etc. that you would like to display, please let us know in order to arrange for table space.  We typically allocate 1/2 table per display.  Plan to bring your projects to show others.

NASS has two registration types: Full and Partial.  The Partial Option is only for Thursday Evening Reception, Saturday Conference Dinner, and the Friday Tour of Pittsburgh Sundials.  The Partial Option does not include admission to the general sessions.  Use the attached form (see below).

Conference Registration Until June 15   June 16 - July 15
  Full Partial   Full Partial
w/Filet Mignon Dinner $302 $192   $327 $217
w/Chicken Marsala Dinner $290 $180   $315 $205
w/Fire Roasted Tortellini Dinner $285 $175   $310 $200

You may send a US dollar check payable to NASS and drawn on a US bank for the registration fee.  Send both form and funds to Fred Sawyer, 27 Ninas Way, Manchester, CT 06040, USA.  Or email the registration information and send US dollars via PayPal This email address is being protected from spambots. You need JavaScript enabled to view it. If you wish to use pounds sterling, please contact This email address is being protected from spambots. You need JavaScript enabled to view it. for instructions.

Download this file (Register_For_Pittsburgh_2018.pdf)Register_For_Pittsburgh_2018[ ]289 kB

Portland Maine WCSH Channel 6 presents local and national news and the usual sports, weather and traffic.  But on a recent 207 broadcast, they reported an invasion ... an invasion of sundialists coming to Portland, Maine for their annual conference and their search for a dial made over a century ago by Albert Crehore that might still be somewhere in Portland. 

Members of the North American Sundial Society (NASS) take the art and science of sundials very seriously.  Watch the video and consider joining NASS for even more sundial adventures.  Visit Portland Channel 6 News:

Ellipsoidal Gnomon SundialThe 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. (Read more in the attached dowloadable PDF)

This year's Sawyer Dialing Prize was awarded to Ing. Gianni Ferrari "for his long career educating the dialing community about the nearly forgotten heritage of ancient Islamic gnomonics and the wide variety of modern analytically developed sundial." (Read more about the Sawyer Dialing Prize)

Download this file (2015 NASS Conference Victoria.pdf)2015 NASS Conference - Victoria[Victoria Conference]1043 kB
Founding Fathers - Washington Dial at Mt. Vernon, VA

In 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. 

Greek Dial from Ai Khanum

Another 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.

Peggy Gunnerson Parallelpiped Dial
Stephen Luecking - Dial Design for DePaul University

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, dedicated as a memorial to a former teacher, Linda Eads.

Download this file (2014_Conference_Indianapolis_IN.pdf)2014 Conference Indianapolis IN[ ]1138 kB
[CHSI - Harvard Collection]

Appropriate to NASS’ visit, Harvard had just recently completed a new major exhibit entitled “Time and Time Again” offering conference members a unique view on the changes in time keeping and the social impact of timekeeping technology.  On Friday afternoon, NASS members followed the Time Trails through the Harvard campus, locating historical sundials “in the wild” and timepieces in the Semitic, Peabody, and Natural History Museums.

The day was finished by two presentations “Trading in Time: European Pocket Sundials Designed for Colonial Use in American Territories by Sara Schechner and “Portable Sundials in Austrian Museums” by Ilse Fabian.

During Saturday a plethora of sundial talks were presented by NASS members, including “Counting the Sunny Hours” by Roger Bailey to a new “Wandering Gnomon Sundial Designn” by Fred Sawyer.  Bob Kellogg presented the making of an animation illustrating the Ibn al-Shatir sundial proposed for Observatory Park in Virginia for the Analemma Society.  One of the most color presentations was Art Paque’s update on Solargraphy, illustrating the technique of forming daily images of the sun a photographic paper that at the last is digitally scanned and preserved.

Download this file (2013_Conference_BostonCambridge_MA.pdf)2013 Conference BostonCambridge_MA[2013 NASS Annual Conference]822 kB

Read more: 2013 Conference - Boston/Cambridge