He was aware of a great difference in the temperature.

Half a dozen men stood about him, and light flakes of snow touched hands and face and melted.

For a moment it was dark, then for a flash a ghastly violet white, and then everything was dark again.
He saw he had come out upon the roof of the vast city structure which had replaced the miscellaneous houses, streets and open spaces of Victorian London.

The place upon which he stood was level, with huge serpentine cables lying athwart it in every direction.

The circular wheels of a number of windmills loomed indistinct and gigantic through the darkness and snowfall, and roared with a varying loudness as the fitful wind rose and fell.