Perpetuum Mobile

I built this model of Drebbel's perpetuum a few years ago, but was really worried I would break it... or it would fail... before I had a chance to film it in action. So I just got an old Nikon S3 (for $13 on eBay), because it has an "interval movie" feature. With the setup shown, I can set the camera to take a picture every 60 seconds, automatically. It will keep taking them until it has 1800 frames, then it will create a .mov format movie from them. The movie is 15 FPS, so that means it will cover one day, six hours, and run for two minutes. This will show the daily variation in the perpetuum. 

Some interesting questions have been answered already, by building this, and then watching it run for a couple of years. First of all, there is a quote by someone who asked Drebbel, (paraphrasing), "How often do you have to add water to it?"... knowing that there is a little opening to the atmosphere in the top. Well his answer is not recorded... but I can say for him, "Not often... maybe a few drops in two years... an ounce at the most".