About midday
But we must be watchful to-day , lord , for that storm covers many miles of country , and the rain is falling in torrents ; and , unless I am greatly mistaken , most of it will find its way into this river . Therefore must we be on our guard against a sudden spate , which may overwhelm us if we are caught unawares . '' The Englishmen agreed , and nothing further was said about the matter , for they were busy making their preparations for the day ; and in due time they embarked and proceeded on their journey . About midday , in confirmation of the old Peruvian 's words , the first of the expected spate revealed itself in a sudden acceleration of the current and a change in the appearance of the water , which became turbid with mud in suspension . Yet although the speed of the current continued to increase gradually , it merely helped the voyagers on their way , for they now seemed to have reached a stretch of the river that was entirely free from rapids , nothing of the kind having been encountered since their start in the early morning . Swiftly the canoe sped down the river , running now at the rate of a good nine miles an hour , and her occupants rejoiced exceedingly , for they were getting over as much ground in a single hour as sometimes cost them a whole day to cover . They began to make light of the precautions which they had observed during the earlier hours of the day , and told each other with glee that if this was the worst a spate could do they would welcome one every day so long as they were bound downstream .