They attended at the time appointed, and after a grave discussion after their fashion, which lasted several days, they agreed to take the expedition under their particular protection, and see it safe to Buenos Ayres; Cruz, on his part, engaging that the Indians who accompanied him should be presented to the Viceroy, rewarded with suitable presents, and sent back in safety to their friends at the conclusion of the service. This pact was ratified with much formality; the hand of Cruz being solemnly placed in that of the most ancient of the Caciques, to signify that thenceforward he was under his special care. Whist the expedition was preparing, Cruz spent a couple of days in an unsuccessful attempt to get to the summit of the volcano in the vicinity of Antuco, which he describes as being then in continual action, and at times burning so strongly as to be visible from a very considerable distance: but he was stopped, and obliged to turn back, by a heavy fall of rain and snow, considered by the Indians as an interposition of the Deity to prevent the examination of a region which they held it to be forbidden to mortals to approach. On the 7th of April (1806), all being ready, the party left the fort of Ballenar, near Antuco, to commence their journey. It consisted of twenty persons, viz., Cruz and four officers, a surveyor to measure the daily distances, and fifteen attendants, besides their Indian escort; having with them carts and horses and all things they might want on the way. Striking across the pampas in as direct a course for Buenos Ayres as the nature of the country would permit, in forty-seven days they arrived at Melinqué,[29] the north-western frontier fort of that province, having travelled, according to their measured daily journeys, rather more than 166 leagues;--adding 68 more for the distance between Melinqué and Buenos Ayres, made the total distance from Antuco to that city, by this route, 234 leagues;--being 75 less than the ordinary post-road from Buenos Ayres to Mendoza. The narrative which Cruz subsequently drew up of this expedition is extremely diffuse, and would be tiresome to most readers from the extreme minuteness with which he has thought it necessary to detail the daily discussions and parleys which, upon every trivial occurrence, took place with the Indians. In a geographical point of view, the most interesting part of it is that in which he describes the rivers which he crossed after descending the Cordillera; from which I have attempted in the map to give an idea of them, differing, as will be seen, from that hitherto adopted. In this I have been also much guided by the observations, in my possession, of the late Dr. Gillies, my correspondent for many years at Mendoza, who had himself been as far south as the river Diamante, and had taken great pains to collect information respecting the geography of that part of the country.