A blue light appeared in the zenith, and in some indescribable manner flickered down near the top of the rod.
It was one of the usual slow sunrises of this time of the year, and the sky, pure violet in the zenith, was leaden to the northward, and murky to the east, where, over the snowy down or ewe-lease on Weatherbury Upper Farm, and apparently resting upon the ridge, the only half of the sun yet visible burnt rayless, like a red and flameless fire shining over a white hearthstone.
There are no more uses of "zenith" in the book.
Show samples from other sources
He met her when her career was at its zenith.
...and the sun passed the zenith and started down.