The name of the Andes, to the traveller who has crossed the giddy passes and scaled the high peaks of this stupendous mountain chain, brings back sensations which are a blend of the pleasurable and the painful. In his retrospect the Cordillera--for such is its familiar name to the inhabitants of the land it traverses--bulks as a thing of varied and almost indescribable moods. It possesses that individuality--menacing, beautiful by turns--which no doubt is an attribute of all mountains, in the recollection of those who best know them. The Andes are no playground, such as some of the mountains of Europe have become, nor are they the object or scene of climbing enterprise and exploration such as bring the Himalayas so frequently before the geographically interested public. Comparatively simple in their structure, it is their enormous length--a wall unbroken, extending for four thousand miles from north to south along the western littoral of their continent--their treeless aridity, their illimitable, dreary, inclement uplands, and, these passed, their chaste snowy peaks, tinged by the rising or the setting sun, that most impress the traveller in those lands they traverse. Here in the higher elevations of these remote fastnesses there are no material comforts for man or beast. Humanity, as far as it has the hardihood to dwell here, is confined to the Indian or the _mestizo_, who has paid nature the homage of being born here, and so can dwell and work in what is his native environment. In the more sheltered valleys it is true that large centres of population flourish; important towns which from their elevation above sea-level--ten thousand or twelve thousand feet--might look down as it were from a dizzy height upon the highest inhabited centres of Europe; whilst, did we establish industrious mining communities on the peak of the Matterhorn or Mont Blanc, we should still be far below some of those places of the Peruvian and Bolivian Andes where minerals are won for the marts of Europe. The Andes consist physiographically of two great parallel chains, forming into three, with lesser parallel undulations, in certain parts of its course; the ranges being joined by _nudos_ or knots, as the transversal ridges are termed; a very well marked structure. In places vast tablelands lie between the high _paramos_ of Colombia, the altiplanicies of Peru, the _punas_ of Bolivia, often studded with lakes, including the enormous Lake Titicaca. In some cases these high uplands between the enclosing Cordilleras are indeed dreary and inclement, sparsely inhabited, and the dweller of the lowlands loves not to sojourn there longer than may be necessary for his purpose. Conversely, the highlander fears the enervating climate of the lowlands.