It was perfectly straight, about three feet in diameter, and extended horizontally the visible length of the tunnel before disappearing into the darkness.
Reaching in with both hands and keeping the pouch horizontal, Langdon lifted it out of the bin.
Stretching his legs out behind him, he walked his feet up the glass wall until he was almost horizontal.
The glass at the far end was thick …. Langdon’s stack had fallen almost to the horizontal when he heard what he was waiting for-a different kind of collision.
When he saw the horizontal shaft of light before him, he realized he was standing a few steps beneath a landing, where the glow of torchlight spilled out beneath the threshold of a door in front of him.
There are no more uses of "horizontal" in the book.
Show samples from other sources
Paintings in which horizontal lines dominate, tend to be relaxing.
The whole thing goes horizontally, too, at least it seems so, and I exhaust myself in trying to distinguish the order of its going in that direction.