Sundials - World's Oldest Clocks

North American Sundial Society


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Students assemble sundialsAvid dialist and former The Grammar School teacher and head of the Putney, VT school, Mac Oglesby guides 6th graders to plan and construct their own working sundials. Oglesby's students learned how to correctly position their dials to display the accurate time throughout the year.

Access this URL (/images/NASS_PaperSundials/NASS-SpiderSundial.pdf)NASS-SpiderSundial.pdf[Mac Oglesby's Sundial for Students]0 kB

Read more: Sundials in Grammar School

In 1636 or 1637 Samuel Foster, a distinguished Professor of astronomy at Gresham College produced a manuscript that describes the construction and use of an analemmatic sundial, a vertical sundial, and a declining sundial. 

The collection of 12 pages on four double leafs each measure 15 x 18 cm.  This manuscript relates to Samuel Foster's most important invention, a computational device known as a dialling scale, and precedes the publication of his second and most significant book in 1638 "The Art of Dialling: by a New, Easie, and Most Speedy Way ..."

Read more: Auction of Rare Foster Manuscript

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To draw your sundial below, convert your latitude into a decimal number for entry. Example: 38 o45' N would be entered as 38.75 Then click the draw button to see the resulting angles for your dial.

When your sundial is drawn, print out the webpage and paste the dial face onto thin cardboard such as from an old cereal box. Fold the gnomon in half and paste it together. Be careful to first fold out the bottom tabs. Apply paste to the tabs and stick onto the base. Make sure that the high end of the gnomon face toward noon ( XII ).

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Quilt of USNO 26-inch RefractorSundials are often created at the instersection of science and art.  Quilting has made its mark as well.  For example in Burnsville North Carolina is the Quilt Block Sundial, painted in bright quilt blocks on a 8x8 foot board above the entrance to the Yancy Common Times Journal Building.

Now comes Altazimuth Arts, an enterprise established by Sara Schechner, well-know historian of science who is curator of Harvard's Collection of Historic Scientific Instruments.  But Schechner is also active in the Studio Art Quilt Associates, Quilters' Connection of Watertown MA, and member of Quinobeguin Quilters guild. As she explains, "Recent quilts are inspired by history and the night sky, the built environment wet within nature, and by the many-faceted meanings of tangible things."

Illustrated is the US Naval Observatory 26-inch refractor made by Alvan Clark & Sons in 1873.  "The inspiration for my quilt was an engraving from a newspaper story celebrating the work of the telescope. The print shows astronomer Simon Newcomb (at the eyepiece) and Superintendent Rear Admiral Benjamin F. Sands (standing) in the dome with the brand new telescope in late fall 1873. The engraving was based on a photograph of the same scene." Visit Schechner site at

Roll-Top Observatory Ribbon Cutting Ceremony Oct 1, 2016

Amid the rain and cloudy skies, on Saturday October 1st, 2016, a ribbon-cutting ceremony officially opened the Roll-Top Observatory at Observatory Park, Turner Farm in Great Falls, VA. Tim Hackman, Dranesville District representative of the Fairfax County Park Authority (FCPA) Board, introduced all those who made the Roll-Top observatory possible through public-community-and-private funding. Initiated in 2007 in collaboration with the Analemma Society, the million-dollar facility was funded in part by the 2008 and 2012 Park Bonds, telecommunications funds, Mastenbrook grant money and a donation provided by Jean and Rick Edelman through the Fairfax County Park Foundation.

Ground breaking for Roll-Top began in 2014 and over the next two years the Roll-Top Observatory design by architects Shaffer Wilson Sarver & Gray of Herndon, VA, was carried out by the construction company Brown and Root of Arlington, VA.

Read more: Roll-Top Ribbon Cutting

Teachers and Architects Draw Sundials for Baltimore SchoolsGrimm & Parker Architects sponsored a "Green Apple Day" on October 15, 2016 to help two Baltimore City Schools - Graceland Park ES/MS and Holabird Academy ES/MS - receive analemmatic sundials on their front sidewalks.  The weather was perfect as teachers and volunteers from G&P chalked out and then painted simple 16 x 5 foot analemmatic sundials.

The sidwalks were aligned true North-South, making dial lay-out easy.  With tape measures in hand, they marked out the focal points and north point of the analemmatic ellipse.  Then, using the time-honored principle of constant distance they used a chalk line between those 3 points to maneuver a piece of chalk following the shape of an ellipse.  For the sundial, the ellipse stretched from 5am to 7pm.  The hour marks were made using two tape measure to check positions that were quickly followed by drawing of the hour circles with a plastic lid.  While volunteers painted the hour circles others chalked out the walkway whose monthly lines and solstices were quickly painted as well. The final touch was the inclusion of the East and West Bailey points that determine the direction of the rising and setting sun.  With a lot of support and good organization, both dials were finished in 3 hours!


This year nearly 300,000 students, parents and teachers attended the 3rd USA Science and Engineering Festival in Washington DC during 25-27 April 2014.   The Analemma Society and the North American Sundial Society jointly featured a very successful booth to encourage science, technology, engineering and mathematics (STEM) through sundials. The Analemma Society and NASS were among hundreds of exhibits from universities, scientific organizations, government agencies, and companies in the defense and educational industries.

Volunteers from the Analemma Society and NASS demonstrated a number of sundial types and provided paper sundial cut-outs that were enjoyed by children, students, parents and teachers alike. They handed out over 1400 of the sundial cut-outs, with the classic horizontal sundial and Briggs polar dial being the most popular.  Especially important were the numerous contacts made with teachers who will now enhance their science classes with sundials.

Volunteers from the Analemma Society and NASS who made this outreach possible were Ken Clark, Jeff Kretsch, Bob Kellogg and Dru Anne Neil.  They did a terrific job explaining that indeed, sundials are the world’s oldest clocks.

In the photo at left NASS member Ken Clark and Analemma Society member Jeff Kretsch show how sundials work while you dialists cut out their sundials.

 ShakespeareFrank Cousins in the appendix of his book Sundials includes a list of references to sundials in Shakespeare. Mechanical timepieces were extremely rare in Shakespeare's day. Cousins credits the list to Professor Delius, The Leopold Shakespeare, Cassel. London, 1887. Here are the full citations taken from the online Complete Works of William Shakespeare.

Read more: Shakespeare's Sundials


  • Sundial Construction
    Various articles describing basic sundial construction and helpful tips and techniques
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  • Sundial Mathematics

    Learn the fundamental mathematics for making sundials.  If you have math anxiety, don't worry.  The formulas only require knowing the trigonometric functions of sine, cosine, and tangent.  Think of these functions as little buttons on your calculator that transform angles into ratios of the sides of a triangle.  Now let's get going.

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  • Cut-Out Sundials
    K-12 Student Projects from simple sundial cut-outs to those requiring trigonometry. 
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  • STEM Outreach
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  • Art and Literature
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  • Draw A Sundial

    Here you can draw your own sundial.  We offer a simple horizontal dial, the same as the cut-out dial except that here you can enter your exact latitude and print out a custom sundial for yourself or for you classroom.

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