CHAPTER XXVIII.
THE FIRST CAMPAIGN IN THE HIGHLANDS.
1820—1821.
Peru may be looked upon as a conglomeration of mountains, enclosed within a sort of triangle, whose base on the third degree of south latitude measures about eight hundred miles, from which it extends southward for about fifteen hundred miles to the southern frontier of Upper Peru on the eighteenth degree of south latitude, where the width of the triangle is reduced to about sixty miles. This territory comprises three zones; the coast zone, the highland zone, and the mountain zone. Along the shores of the Pacific ocean lies a belt of sand, never more than sixty miles in width, cut by twenty-three rivers, which flow from the Highlands to the sea through fertile valleys, separated by deserts of sand-hills, moved to and fro by the winds; on which sand-hills there is no sign of vegetation, neither are there birds in the air, nor reptiles on the earth; a far-stretching series of deserts on which rain never falls. This is the region now in part occupied by San Martin and his army.
On the east of this "Tierra Caliente" rises abruptly the western range of the Andes; further still to the east stretches the huge line of the true Cordillera. Between these ranges there lies in Upper Peru a vast tableland, but in Lower Peru the intervening space is intersected by numerous valleys and by the Andine lakes, which are sometimes as much as 16,000 feet above the level of the sea.
Under the Viceroys, Lower Peru was divided into eight
