National Geographic 1920's Lot of 6

National Geographic 1920's Lot of 6 October 1923 - The Automobile Industry Methods That HAve Revolutionized Manufacturing and Transformed Transportation; The Empire of the Risen Sun; The Cause of Earthquakes; How the Earth Telegraphed Its Tokyo Quake to Washington August 1924 -Twentysix Illustrations In Full Color; Discovering the Oldest Statues in the World; Adventurous Sons of Cadiz; Moorish Spain; From Grandad to Gibraltar a Tour of Southern Spain May 1925 (pink discoloration on cover) - Sixteen Pages of Illustrations in Full Color; Through the Back Doors of Belgium; Ferns as a Hobby; Marvels of Fern Life; Tracking the Columbian Ground Squirrel to Its Burrow; Helsingfors A Contrast in Light and Shade November 1925 - Special Map Supplement of the Arctic Regions (included); 32 Illustrations in Full Color; The MacMillan Arctic Expedition Returns; Flying Over the Arctic; History's Greatest Trek; Sun Painted Scenes in the Near East April 1927 - twenty Nine Illustrations In Full Color; The Races of Domestic Fowl; Foul of the Old and New World; America's Debt to the Hen; The Chinese Farmers Since the Days of Noah July 1927 - Sixteen Pages of Illustrations in Full Color; Sindbads of Science The Narrative of a Windjammer's Voyage Among Islands of High Adventure in the South Atlantic; Strange Habits of Familiar Moths and Butterflies