REGISTERED LETTER SENT FROM CONSTANTINOPEL TO LUGANO

BY GERMAN IMPERIAL POSTAL SERVICE

MOST PROBABLY BY TRAIN 

PASSING THROUGH BUCAREST AS A PRECURSOR OF THE ORIENT EXPRESS

(THE ORIENT EXPRESS WAS LAUNCHED THE FOLLOWING YEAR, IN 1883)

"BUCAREST" CANCELLATION CLEARLY UNDER THE SWISS "AMBULANT" CANCELLATION

 A UNIQUE SHOWPIECE!