Solar Observatory: Part 1

So here is my Solar Observatory. I'm slightly embarrassed to say it cost me $42 in parts. If I had driven another 15 miles or so for the parts, it would probably have been cheaper, but with gas prices what they are...

I still need to buy a compass and an angle measuring device to make it complete. I may mount the bottom in a small slab of concrete. I haven't decided yet.

The board on top has a 1 inch hole drilled in it to allow the sun to shine into the end of the 1/2 inch pipe, while it casts a shadow onto the target board attached to the other end.

The street L at the top of the stand is greased so it will allow horizontal and vertical rotation. When it is lined up with the sun, a round spot of sunlight shows up on the target board as it does in this picture.

There is an incredible amount of flex in the stand pipe, and the tolerance of the sight is so small that it takes a bit of hunting to get it to line up. finally at 10:12 AM I got it to line up.

By 10:14 AM the angle has changed enough to reduce the spot to a half circle, and by 10:16 AM, it was gone completely.

I plan to do my measuring on or near 5 specific days.

#1: The summer solstice, June 21st.
#2: Half way between the summer solstice and the autumn equinox, August 5.
#3: The autumn equinox, September 22.
#4: Half way between the autumn equinox and the winter solstice, November 6.
#5 The winter solstice, December 21.

Since the spring equinox is nearly the same as the autumn equinox, I can skip those.

I'll have to find the rest of the parts for it in the next week so I don't miss this years summer solstice.