were placed at regular distances expressly to prevent separation.  One party was frequently heard hallowing from an apparently fathomless ravine, to their comrades passing over some high projecting summit, to know if they were going right.  These would answer with their trumpets; but it often occurred that both parties had lost their road.  The frequent sound of trumpets along the broken line—­the shouting of officers to their men at a distance—­the neighing of horses, and the braying of mules, both men and animals being alike anxious to reach a place of rest, produced a strange and fearful concert, echoed, in the darkness of the night, from the horrid solitude of the Andes.  After many fruitless attempts to discover the proper route, a halt until daybreak was usually the last resource.  The sufferings of the men and animals on those occasions were extreme.  The thermometer was generally below the freezing point, amidst which they were sometimes overtaken by terrific snow-storms.  These difficulties and hardships were not so severely felt by the infantry, for, unincumbered with the charge of horses, it was an easy matter for them to turn back, whereas it was often impossible for the cavalry to do so, the path on the mountain-side being generally too narrow to admit of horses turning round.  It happened more than once, that the squadron in front, having ascertained that it had taken a wrong direction, was nevertheless compelled to advance until it reached some open spot, where the men were enabled to assemble, and wait for the hindmost of their comrades, and then retrace their steps.  After having pursued this plan, the troops have met another squadron following the same track; and, under such circumstances, it has required hours for either to effect a countermarch.  In this complicated operation many an animal was hurled down the precipice and dashed to pieces, nor did their riders always escape a similar fate.

In the mountainous regions of the interior, nature presents difficulties which, though of a different description, are equally as appalling as those experienced on the coast.  The sheds erected at pascanas (or halting places) in the vast unpeopled tracts of the bleak mountain districts, and on the table lands, were inadequate to afford shelter to more than a small number, so that the greater part of the troops were obliged to bivouac sometimes in places where the thermometer falls every night considerably below the freezing point, and this throughout the year; whereas it often rises at noon, in the same place, to 90 degrees.  It may be readily imagined what must have been the sufferings of men, born in, or accustomed to, the sultry temperature of Truxillo, Guayaquil, Panama, or Cartagena.  The difficulty of respiration, called in some places la puna, and in others el siroche, experienced in those parts of the Andes which most abound in metals, was so great at times, that, whilst on the march, whole battalions would sink down, as if by magic, and it would have been inflicting death to have attempted to oblige them to proceed until they had rested and recovered themselves.  In many cases life was solely preserved by opening the temporal artery.  This sudden difficulty of respiration is supposed to be caused by occasional exhalations of metalliferous vapour, which, being inhaled into the lungs, causes a strong feeling of suffocation.