Hail, Twilight, Sovereign Of One Peaceful Hour

HAIL Twilight, sovereign of one peaceful hour!
Not dull art Thou as undiscerning Night;
But studious only to remove from sight
Day's mutable distinctions.--Ancient Power!
Thus did the waters gleam, the mountains lower,
To the rude Briton, when, in wolf-skin vest
Here roving wild, he laid him down to rest
On the bare rock, or through a leafy bower
Looked ere his eyes were closed. By him was seen
The self-same Vision which we now behold; 
At thy meek bidding, shadowy Power! brought forth
These mighty barriers, and the gulf between;
The flood, the stars,--a spectacle as old
As the beginning of the heavens and earth!