cover 1891 (23 Aug.) XU5 to Prof. Collett, Christiania, Norway, from Dr. N. Grøndal of the Icelandic Natural Science Society, bearing 20a. greenish blue tied by c.d.s. (23.8) Type C1 with framed "SHIP LETTER" adjacent and Edinburgh transit c.d.s. on reverse. Very fine and believed to be the earliest recorded use of this printing on cover. F. 15, S.Kr. 6,000+. Photo