Back in August I had a short post with some photos of the Palomar Day Crew performing some maintenance on the shutter rails for the dome of the 200-inch telescope. One of the guys doing the work took this cool picture that he was willing to share with the readers of Palomar Skies.
That "big" gear on the left is a part of the mechanism that opens the dome. From the perspective of the photographer it almost seems to rival the horseshoe in size, but then again he was right next to the gear and the horseshoe was very much in the background.
Thanks to Drew for sharing the photo.