It grew steadily darker, the light fading quickly from the overcast sky.
Even as they were speaking Flint noticed that it grew steadily darker.
It was just past sunset now, and the office was growing steadily darker.
Again in the water, Kaloro preceded us along a natural rock tunnel which grew steadily darker and then brighter.
The sky, which had been dark all day, was growing steadily darker.
Hauptman's face had grown steadily darker, and Honor paused, regarding him calmly.
As the day progressed, the clouds became steadily darker until nearly all light was obscured.
Ever since they left the surface it had become steadily darker.
His view of the prospects at New York grew steadily darker.
As they rode in beneath the cloud, it grew steadily darker.