How does Montag describe Clarisse's face?

From the text:

She had a very thin face like the dial of a small clock seen faintly in a dark room in the middle of a night when you waken to see the time and see the clock telling you the hour and the minute and the second, with a white silence and a glowing, all certainty and knowing what it has to tell of the night passing swiftly on toward further darknesses but moving also toward a new sun.