mackerel-sky

The sun shines; serenely westering, in smokeless mackerel-sky: Paris is as if sleeping, as if dead: -- Paris is holding its breath, to see what stroke will fall on it.

The French Revolution Thomas Carlyle 1838

-- The first part of the night till the setting of the moon was very clear; after this it became cloudy, but cleared again at sunrise, with the exception of some mackerel-sky and stratus to the north-west.

Journal of an Overland Expedition in Australia : from Moreton Bay to Port Essington, a distance of upwards of 3000 miles, during the years 1844-1845 Ludwig Leichhardt 1830