He followed the general course of the Bhotia-Kosi River, which he was obliged to cross fifteen times within twenty-five miles [40 km]. At one place the river ran in a gigantic chasm, the sides of which were so close to one another that a bridge of 24 paces was sufficient to span it. Near this bridge the precipices were so impractible that the path had to be supported on iron pegs let into the face of the rock - the path being formed by bars of iron and slabs of stone stretching from peg to peg and covered with earth. This extraordinary path is in no place more than eighteen inches [460 mm], and often not more than nine inches [230 mm] in width, and is carried for more than a third of a mile [500 m] along the face of the cliff, at some 1,500 feet [500 m] above the river, which could be seen roaring below in its narrow bed. The Pundit, who has seen much difficult ground in the Himalayas, says he never in his life met anything to equal this bit of path. (report of Montgomerie to the Royal Geographical Society)