Of all the general works on Peru none has greater weight than _Peru; Beobachtungen und Studien_ (1893) by E. W. Middendorf. He has exploited the country in a large, three-volume work with such German thoroughness that hardly a fact has been left for subsequent writers to disclose. I have referred to it constantly. Other shorter, general studies of the country are Von Tschudi’s _Reisen durch Südamerika_, giving much attention to folk-lore, and _Twenty Years’ Residence in South America_ (1825) by W. B. Stevenson, secretary to Lord Cochrane. He traveled far and wide in Peru and made observations in regard to remote details. Typical of descriptive writings is _Two Years in Peru_ (1876) by T. J. Hutchinson. Various general works by Bernard Moses and his publications in the _University of California Chronicle_ are valuable, notably his work on the produce of the mines. Reliable observations on ruins are those made by E. G. Squier in his _Peru: Travel and Exploration in the Land of the Incas_, by Mariano Rivero y Juan de Tschudi in _Antiguedades Peruanas_, and by Charles Wiener in _Pérou et Bolivie_. Studies of ruins in particular localities have been made by many archaeologists; for example, on Tiahuanacu, L. Angrand, in _Antiquités Américaines_, though his book is now out of date, Adolph F. Bandelier in his _Islands of Titicaca and Koati_, Max Uhle, with whom I visited some of the ruins, on Tiahuanacu and Pachacamac, and Hiram Bingham in recent explorations. Sir Clements Markham has spent more than fifty years studying every stage of Peru’s history from the time when it was a land of myth to the Chilian war. His researches as well as his careful translations have been published in a series of volumes. Authorities on various periods of the history are legion. Relating to pre-Inca times, in which studies of myths and theories of ruins are intermingled, original sources are the _Memorias Historiales_ of Montesinos, first published in French in 1840, and Cieza de Leon, the soldier, whose _Crónica del Perú_ (1553) is authority on the Incas. Some modern scientists who have written about the pre-Inca period are Ernest Desjardins in his _Pérou avant la Conquête Espagnole_, Tylor’s _Primitive Culture_, Meyen’s _Uber die Ureinwohner von Peru_, and Brinton in his _Myths of the New World_ and other works. Many persons are studying the legends, as, for instance, Professor Liborio Zerda of the University at Bogotá. The _Miscelaneas Australes_ of Miguel Cavello Balboa, a soldier, is an original source for knowledge of the remote Chimus. _Das Reich der Chimus_ by Otto von Buchwald, and especially _Das Muchik oder die Chimu Sprache_ by Doctor Middendorf, who quotes largely from Calancha and Carrera, are modern authorities.