细节
cover 1848 (3 Jan.) entire from Berbice to London showing fine h.s. "½" (Type 10) and, on reverse, double-arc. d.s. (Type 6) just affected by removal of seal, and 1857 entire letter from Berbice to Andover, rated "6d" and showing, on reverse, a superb upright strike of the double-arc d.s. (Type 7)