Analysis of Moonlight

What time the meanest brick and stone
Take on a beauty not their own,
And past the flaw of builded wood
Shines the intention whole and good,
And all the little homes of man
Rise to a dimmer, nobler span;
When colour's absence gives escape
To the deeper spirit of the shape,

-- Then earth's great architecture swells
Among her mountains and her fells
Under the moon to amplitude
Massive and primitive and rude:

-- Then do the clouds like silver flags
Stream out above the tattered crags,
And black and silver all the coast
Marshalls its hunched and rocky host,
And headlands striding sombrely
Buttress the land against the sea,
-- The darkened land, the brightening wave --
And moonlight slants through Merlin's cave.