The achievements of the explorer are among the most important, as they are among the most fascinating, of human heroisms. The qualities of mind and body necessary to his task are rare and admirable. He should have many sides and be strong in each,--the rounded man that Nature meant man to be. His body need not be as strong as Samson's, nor his mind as Napoleon's, nor his heart the most fully developed heart on earth; but mind, heart, and body he needs, and each in the measure of a strong man. There is hardly another calling in which every muscle, so to speak, of his threefold nature will be more constantly or more evenly called into play. It is a curious fact that some of the very greatest of human achievements have come about by chance. Many among the most important discoveries in the history of mankind have been made by men who were not seeking the great truth they found. Science is the result not only of study, but of precious accidents; and this is as true of history. It is an interesting study in itself,--the influence which happy blunders and unintended happenings have had upon civilization. In exploration, as in invention, accident has played its important part. Some of the most valuable explorations have been made by men who had no more idea of being explorers than they had of inventing a railroad to the moon; and it is a striking fact that the first inland exploration of America, and the two most wonderful journeys in it, were not only accidents, but the crowning misfortunes and disappointments of the men who had hoped for very different things. Exploration, intended or involuntary, has not only achieved great results for civilization, but in the doing has scored some of the highest feats of human heroism. America in particular, perhaps, has been the field of great and remarkable journeys; but the two men who made the most astounding journeys in America are still almost unheard of among us. They are heroes whose names are as Greek to the vast majority of Americans, albeit they are men in whom Americans particularly should take deep and admiring interest. They were Alvar Nunez Cabeza de Vaca, the first American traveller; and Andres Docampo, the man who walked farther on this continent than any other. [Illustration: WHERE ZALDIVAR STORMED THE CITY. _See page 135._]