a great chocolate-coloured pall lowered over heaven , but the wind was continually charging and routing these embattled vapours ; so that as the cab crawled from street to street , mr. utterson beheld a marvelous number of degrees and hues of twilight ; for here it would be dark like the back-end of evening ; and there would be a glow of a rich , lurid brown , like the light of some strange conflagration ; and here , for a moment , the fog would be quite broken up , and a haggard shaft of daylight would glance in between the swirling wreaths .