In Nature, 90-169 and additional subsequent pages is the account of a man, Charles Tilden Smith, who saw “two stationary dark patches upon clouds” on April 8, 1912 at Chisbury, Wiltshire, England. These patches were triangular and varied in size, but “kept the same position upon different clouds as cloud after cloud came along.” He watched them for more than a half hour. Other correspondents said this was something intercepting the sun’s rays, perhaps mountains or pilot balloons (this from a meteorologist). Fort refutes this explanation by saying, “If, to the west of Chisbury, a stationary object were high in the air, intercepting the sun’s rays, the shadow of the stationary object would not have been stationary, but would have moved higher and higher with the setting of the sun.”
–Charles Fort, The Book of the Damned, p. 266-268 (The Complete Books of Charles Fort, Dover, c1974).