posted on Jan, 19 2010 @ 06:00 AM
"The German on the ground knows us by the pearly white scarf which every plane flying at high altitude trails behind like a bridal veil. The
disturbance caused by our meteoric flight crystallizes the watery vapor in the atmosphere. We unwind behind us a cirrus of icicles. If the atmospheric
conditions are favorable to the formations of clouds, our wake will thicken bit by bit and become an evening cloud over the countryside."
--
Flight to Arras, by Antoine de Saint-Exupery. c. 1942
Of course, for a really old reference,
here is a description (on the
lower-right of the page) of persistent contrails from July, 1921: