Sundials - World's Oldest Clocks

North American Sundial Society

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!