classic waka stream

ながき夜をあかしの浦に焼く塩の
けぶりは空に立ちやのぼらぬ
Roma-ji

Nagaki yo o Akashi no ura ni yaku shio no kemuri wa sora ni tachi ya noboranu

English Translation
Through the long night I
keep watch till dawn at Akashi
where they burn the salt
Does the smoke of it not rise
and stand up against the sky
Meaning
Through the long night I keep watch till dawn at Akashi, where they burn the salt. Does that smoke not rise and stand against the sky?
Commentary
77 Tonight of All Nights She Goes

To the same Katsura Princess, Minamoto no Yoshitane composed "Nagaki yo o Akashi no ura ni yaku shio no kemuri wa sora ni tachi ya noboranu". While they were meeting in secret in this way, the princess was invited to the retired emperor's gathering on the night of the full moon; and as she was about to go, Yoshitane, seeing that it would put an end to their meeting, begged her not to go that night at least. But she could not stay away when the retired emperor had summoned her, and she left in haste, whereupon Yoshitane composed "Taketori ga yoyo ni nakitsutsu todomekemu kimi wa kimi ni to koyoi shimo yuku". That is the whole of the section.
The Katsura Princess lived at Katsura, has poems in the twentieth and twenty-sixth sections, and appears in the seventy-sixth. Minamoto no Yoshitane was the man visiting her, who spends a night outside her gate in that section. The retired emperor's residence is the palace of an emperor after his abdication.
The setting is the period of Yoshitane's secret visits to the Katsura Princess.
The prose records nothing further of what prompted it. All we are told is that he composed it for her.
Afterwards the princess is summoned to the retired emperor's gathering on the night of the full moon, and he tries and fails to keep her from going.

The word in the second line means both keeping watch until daybreak and the place name Akashi, so that a long night and a stretch of shore are held in one word.
Burning salt is the boiling down of sea water on the shore, and the smoke of it leads into the line that follows.
Smoke from the salt fires had long stood in poetry for a man burning with love; the smoke is the feeling made visible.
The closing asks whether it does not rise — whether his feeling, turned to smoke, is not visible from where she is. From keeping watch to a place name to smoke, the poem gathers the whole run of their secret nights.
Source
Yamato Monogatari
Other