about five o'clock in the evening
The choice of the place to step on was not made without trouble . They marched from preference on the edges , which were covered by a thick and tough grass . Often the support failed , and they sank to the knees in the slime . At last , about five o'clock in the evening , the marsh being cleared , the soil regained sufficient firmness , thanks to its clayey nature ; but they felt it damp underneath . Very evidently these lands lay below the neighboring rivers , and the water ran through their pores . At that time the heat had become overwhelming . It would even have been unbearable , if thick storm clouds had not interposed between the burning rays and the ground .