First Through the Grand Canyon: Being the Record of the Pioneer Exploration of the Colorado River in 1869-70. E-book. Formato PDF John Wesley Powell   -  Forgotten Books, 2017  - 

The Colorado River of the West is formed in southeastern Utah by the junction of the Grand and Green rivers. For hundreds of miles it flows through a series of profound chasms, in many places from 4,000 to 6,000 feet deep, and rising nearly vertically for a considerable distance above the water. These canons are from one to fifteen miles wide at the top. The most famous of them is the Marble-Grand canon (really continuous, although it goes under two names, the Marble and the Grand). Through this vast gorge the Colorado drops 2,330 feet in 283 miles, the current sometimes attaining a velocity of twenty-five miles an hour. The river itself varies in width from seventy-five feet to a quarter of a mile. In the narrowest places it has at times a depth of over 100 feet.

On Primitive Institutions. E-book. Formato PDF John Wesley Powell   -  Forgotten Books, 2017  - 

Two radically distinct methods of regimentation are found extant in the world and recorded in the history of the past; these may be known as the tribal system and the national sys tem. By the tribal system men are organized on the basis of kinship, real or artificial. By the national system men are organized on the basis of territory. Thus kinship groups are found in tribal society, territorial groups in national society. In history, transitional forms are found, the most important of which are feudal. Thus, feudal society exhibits both methods, and forms a connecting link in the evolution of tribal into national government. In savagery, families are organized into clans, and clans into tribes, and tribes into confederacies. Sometimes, intervening units are discovered, but the family, clan, tribe and confederacy are always discovered. In barbarism families, gentes, tribes.