I came across this remarkable observation mentioned in Sir Robert Ball’s “Story of the Sun” (1893)
On 7th October 1892 M. Trouvelot observing from Meudon observatory records observing a black protuberance. He describes the spout of of ejected material as inky black, the temperature of its constituents, whatever their nature, having been probably much below that possessed by the ordinary luminous prominences. He also states, similar phenomena have been noticed by him on certain other days.
Bearing in mind what we know today, what do you think he saw? A shadow of a prom? Has Hinode or SDO ever seen such a thing?
David