Their idea was to give humanity a sense of continuity over the long term by building a clock which would run for 10,000 years. Talk about a mythic adventure!
It was the one thing I wanted to get into The Boycott and for which there was no narrative room. Turns it out it was because it needed its own show. Kind of like how The Eden Project started out at The Lost Gardens of Heligan, but then took over a whole industrial clay mining pit of its own.
Anyway, turns out that Stewart Brand gave a great talk about the clock at TED 2004, but it's only just been posted on line (thanks, John, for alerting me). And here it is. I particularly like the description of the Seven Stages of Mythic Adventure (super-theatrical!), the images of the Bristlecone Pine, the word "seek" as a place name (kind of like the word "reach"), and the Native American idea that if you want to think in the long term, "look to the mountain."