Volunteers Needed!

I'm looking for volunteers to work on the Mosaic Sundial during May.

Here's some opportunities:
Monday-Thursday, any time between 9 and 3, work indoors on arranging tiles. This is kind of like doing a puzzle without any rules. Come for an hour and try your hand at it, or show up every day. The set-up is in the hall near the preschool.

Sunday May 15, during Parent Work Day, we will be setting tiles in thinset morter on the sundial itself. Come join me for an hour or all day. I hope to film some of this action. Keep your fingers crossed for good weather.

Robyn

Annalemna

What the heck is an analemna? Is that the name of a new BCSIS kindergartener? Just kidding.

The lopsided figure 8 that you see at the bottom of the sundial, in the black non-shadowed area, is called an Analemna. It is a representation of the path of the sun throughout the year.

If you could record the position of the sun in the sky at the same time every day, you would notice that the sun takes a rather strange path. You might notice that at certain times throughout the year the sun's position not only varies higher and lower (North and South) as you would expect with the change of the seasons, but also slightly east and west. This figure-8 path that the sun makes in the sky is called the analemma. In the movie "Castaway", Tom Hank's character marks an analemna on the wall of his cave, and uses it to calculate the bast time to attempt an escape from the island.
For more information, and in-depth explanation, and some mathematical fun, see http://www.analemma.com/Pages/framesPage.html

Finding North

One of the things we must do before we lay the tiles on the sundial is to find true north.

True north is not the same thing as magnetic north. If you use a compass to find north on a large sundial, the sun shadow will be inaccurate. This is because of magnetic declination, (sometimes called magnetic variation) which is the angle between magnetic north and true north. Magnetic declination changes over time and with location. If you use a compass to find north, you must correct for your particular declination.

For the latitude and longitude at Aurora 7 schoolyard, according to the NOAA site, the declination is = 9° 5' E changing by 0° 8' W/year.You can also find north by casting shadows and measuring them. Click on this for how.
Or we can cast a shadow at exactly noon (or 1:00, with an hour added for Daylight Savings time) because the sun will be exactly south at that particular time, and the shadow will be exactly north.

Another method is to go out on a clear night and look for the north star.

Because we are gong to measure north by casting a shadow, we are using a large tripod on the sundial. A big object= a big shadow. You can tell your friends that is what the tripod is doing.

Beautiful Handmade Tiles for the Sundial

Check out these beautiful tiles.

Here they are, in boxes and strawberry flats. Lots and lots and lots of tiles!

These are the tiles that were created by the kids at BCISIS and High Peaks last year--with lots of help from parent volunteers.

Right now, they are stacked up on a shelf in the new little red shed. We will soon put the tiles on the cement slab that will become the sundial..

This is going to be a joy to make and really fun to explore! By the way, if you are interested in helping create the sundial, click on the volunteer tab at the top of the page.

Robert Adzema Sundial

Robert Adzema is an artist who has been working for years with sundials, and has built many kinds of sundials. Many of them are large and in public places. One of his most colorful sundials is at the Brooklyn Childrens' Museum. It is located outside the museum, and it is constructed of German glass tiles. The colors are bright and childlike, and the theme of a sun in a bright blue sky is the inspiration for my sundial. Robert has offered encouragement on this project, which was invaluable at the beginning stages of design and grant-seeking. thanks Robert!

Making the Tiles with Kids

Most of the tiles that are used in this mosaic have been hand made by the children who attend Aurora 7 schools: High Peaks Elementary and Boulder School of Integrated Studies. The clay was rolled out on a slab roller. The top was smoothed, and then the large sheets of clay cut into 6"x6" squares. Each and every child painted the tiles in a lovely range of colors. The tiles were then cut into smaller pieces, to allow for more detailed mosaic designs. Some of the tiles were cut into triangle shapes, because the round shape of the mosaic needs some tiles that are not square! Teachers came to the tile-painting classroom and painted tiles also. They were assigned a number (the hour) or a domino-like representation of the number. Though we had to lure them into the room with a promised luncheon, they had fun and worked diligently, creating the numbers that will define the sundial's times.

Cement Poured for Sundial

You can see the place where the sundial will be created if you peer through the fence around the Outdoor Classroom work area. This is the view that most of us have seen as we walk by the fence by the sidewalk, or around the fence that secures the construction area.

The construction workers are getting ready to pour the cement for the mosaic sundial base. Here is the form that will hold the cement for the sundial base. The strong wooden walls make a form that will hold the cement while it sets up.

This is the cement in the form, freshly poured, still a little wet-looking. The surface of the cement is left rough, so the thin-set morter will stick to the cement better than if it was smooth. The wooden structure is taken off when the cement is hard to the touch. Here it is... the big circle of cement that will make up the base of the mosaic sundial. This photo is taken from the south side, with the western part of the school inthe background. The cement will have to cure for about 4 weeks before we can affix the tiles. However, it is already hard and solid enough to walk on and watch how your shadow falls. And now...the shadow on the sundial. Doesn't look like much now! Just wiat until we can tell time and look at the beautiful tiles.