It is remarkable that, while along the coast of Peru the eye wearies in looking at sandy plains and hills, we no sooner pass the river Tumbez than the face of nature changes: in the former range all looks arid and scorched; in the latter country all is verdant and sappy. The coast of the Equatorial Republic presents to the eye well-wooded plains; while on the coast and in the valleys of the western side of the Peruvian territory, trees, when not reared by man, are only to be met growing in favoured places in the vicinity of springs and rivers. Piura, the most northern province of Peru along the shores of the Pacific, is celebrated for its remarkably dry atmosphere; but in a rainy year, which seldom happens in this province, the pastures that suddenly spring up are surpassingly luxuriant,—the very sand-fields, “arenales,” after one or two days’ rain, unfold an exuberance of life and vegetation. The temperature of the low valleys on the coast of Peru may be said in general not to exceed 82° of Fahrenheit in summer, nor to descend much under 60° in winter.[1] Where, however, high hills closely overhang the sandy plains or dry “pampas,” it is difficult to say to what degree the thermometer may fall during night, when the rush of cold air from the upper regions is in proportion to the degree of radiation from the plains, and the force with which the sun’s rays during the day had struck on the scorched ground. So intensely on such occasions does the traveller feel the transition, that, when benighted on desert places, he is sometimes compelled by the keenness of the cold to dismount, and bury himself up to the neck in the warm sand, until a returning sun again befriend him on the morrow, and encourage him to pursue his trackless way. In Lima, the capital of Peru, neither the extremes of heat nor of cold are ever experienced;[2] an advantage which it partly owes to its very splendid back-ground of mountains, rising one above another to the skies. In winter, the thermometer of Fahrenheit never, in the centre of the town, falls under 60° in the shade; and, during summer, we have never seen it rise above 82°,—its usual station being about 80° in well-aired apartments. The ordinary difference between the fall of the night and day thermometer is only from three to four degrees when the thermometer is placed inside a common barred window without glass, and opening into a veranda or corridor, such as is usual in Lima houses, for the sake of free ventilation. In the sultry month of February, the thermometer, if placed on the open and flat-roofed house-top of mud plaster, rarely ascends above 112°; and at this season, when the hot noon-day air may be said to be fanned by the countless “gallinazas,” or vultures, that wheel and sweep in mid-sky, the canopy overhead is curtained with white light clouds that happily protect the city and its inhabitants from the too scorching beams of a tropical sun.