Darkeningly

In addition, he wore […] a soft black hat that hung darkeningly over his eyes.

Up from the floor, from the depths of the corners, […] along the tin-pipe reaching into the ceiling, crept the summer darkness. Only at a blotch of sunlight did it hesitate, tentative as a leaf-flicker on the whitewashed plaster, then moment by long moment it seeped in darkeningly.