Analysis of information sources in references of the Wikipedia article "Cyanometer" in English language version.
Oh! "darkly, deeply, beautifully blue,"
As some one somewhere sings about the sky,
And I, ye learned ladies, say of you;
They say your stockings are so (Heaven knows why,
I have examined few pair of that hue);
Blue as the garters which serely lie
Round the Patrician left-legs, which adorn
The festal midnight, and the levee morn.
[...]
Humboldt, "the first of travellers," but not
The last, if late accounts be accurate,
Invented, by some name I have forgot,
As well as the sublime discovery's date,
An airy instrument, with which he sought
To ascertain the atmospheric state,
By measuring "the intensity of blue:"
Oh, Lady Daphne! let me measure you!— Lord Byron, Don Juan (1821), Canto IV §§ 110, 112; p.127