Here's a look at what the coursing of stones stepping around the temple looks like, as I'm standing on the edge.
You can just see the black band of granite that is already 'stepped out' below the dozen or so courses forming the beginning of the dome. The combination of the corbeling above that band, and the darker area of corbeling below that, (part of the curved lower wall) comes to just over twelve inches of 'overhang', already.
That leaves about 15 more horizontal feet of corbeling to go to stretch to the middle. It's best, however, to start being careful not to step too near the edge already.
