Custom Consulting Work

Pipe Dial

In 2000, I consulted on the design of Vermont sculptor Kate Pond's equatorial pipe dial "Come Light Visit Me." The one-hour gap near the top of the dial defines two gnomons (and two shadow lines), one for reading standard time in the winter, and one for reading Daylight Savings in the summer. The dial is oiled steel, and is designed for around 45 degrees latitude. Pipe dials such as this were originally conceived in England by Chris Lusby-Taylor.

12" diameter maquette of equatorial pipe dial by Kate Pond 4 foot diameter finished sculpture of Kate Pond's equatorial pipe dial "Come Light, Visit Me."


Analemmatic Dial

Here is a 10 foot diameter analemmatic dial I made for Edmunds Elementary School in Burlington, Vermont to commemorate the retirement of their science teacher. The child stands on the date, and they read the time from their own shadow. The 8:00 AM apple has a worm emerging called the "8:10 worm." This worm corrects for the equation of time to accurately denote the time that school begins--it is 8:10 when the childs shadow crosses the portion of the worm reading the current month.

Analemmatic Dial at Edmunds Elementary School in Burlington, Vermont The 8AM apple has a worm that tells the time that schoool starts, 8:10, corrected for the Equation of Time. It is 8:10 when the shadow is centered over the proper month.


Solstice/Equinox marker

Here is another project I worked on with sculptor Kate Pond called "Odyssey of Light" at a meditative labyrinth at the All Saints Church in South Burlington, Vermont. Focusing mirrors are placed atop separate poles 35 feet from the center of the labyrinth. Each mirror casts a line of light that wanders over the labyrinth throughout the year and rarely intersect. But on the Winter Solstice and on both Equinoxes, the lines cross at noon at the labyrinth's center, forming a transient cross--sort of a modern day Stonehenge. The mathematical modelling to design and align the mirrors was quite involved, and made extensive use of spherical trigonometry.

Winter Sostice Cross Fall Equinox Cross Mirrors and poles. Upper mirrors are for the Equinoxes, and lower mirrors for the Winter Solstice. Photos by Fred Stetson
This shows the general layout of the Labyrinth and mirrors. To watch a time lapse movie of the beams crossing September 21, 2005, click here. The movie compresses 80 minutes into 5seconds.


Vertical Sundial for Public School

Precision Sundials was asked to provide a layout for a vertical sundial for a public school building in Lampeter, PA, as well as a graph to convert sundial time into civil (clock) time.

On the left is some of the detailed information information provided by Precision Sundials for a vertical sundial for the school's front facade, which faced 188.5 degrees south/southwest. On the right is the final design produced by Lewis & Associates Architects of Lancaster, PA, based on that information. The finished installation is shown below. The dial was built by craftsfolk chosen by the Architect. (photocredit: Charles Yohe)

Below are 2 versions of Equation Of Time graphs, calculated to include the school's longitude correction.

-Bill Gottesman 10/2005