PREFACE
EXPLORERS
COLUMBUS DISCOVERS AMERICA
Justin Winsor
LEWIS AND CLARKE REACH THE PACIFIC OCEAN
THE SOURCES OF THE MISSISSIPPI
Brigadier-General Zebulon M. Pike
MANILA IN 1842
Lieutenant Charles Wilkes
THE ASCENT OF MOUNT TYNDALL.
Clarence King.
THE GRAND CAÑON OF THE COLORADO
Major John Wesley Powell
