1 adverbs to describe how to quiverings

The fiery, gloomy curtain of flame that hung quaking overhead, and down away into the Southern sky, began to thin and contract; and, in it, as one sees the fast vibrations of a jarred harp-string, I saw once more the sun-stream quivering, giddily, North and South.

1 adverbs to describe how to  quiverings  - Adverbs for  quiverings