Delacroix, on researchers at Cambridge, 1850:
“Since the light of the star which was daguerreotyped
took twenty years to traverse the space separating it
from the earth, the ray which was fixed on the plate
had consequently left the celestial sphere a long time
before Daguerre had discovered the process by
means of which we have just gained control of his light.”
Edit: Ha, I see James posted this ten years ago; I first read it in 2004 in Sontag’s “On Photography”.