He became aware of some faint, remote, dark specks floating lightly through the outer air.

They came down towards him, fitfully, eddyingly, and passed aside out of the uprush from the fan.

A gleam of light flickered, the specks flashed white, and then the darkness came again.

Warmed and lit as he was, he perceived that it was snowing within a few feet of him.
Graham walked across the room and came back to the ventilator again.

He saw the head of a man pass near.