The Indus is crossed by a swing-bridge of willow twigs, which leads from the villages on the north bank to the fort of Rondu. From Thawar I descended to this bridge, in order to ascertain the boiling-point of water, so as to get an approximation to the elevation of the bed of the river. It is thrown across a remarkably contracted part of the river, where it flows between perpendicular rocks rising several hundred feet out of the water, and the path by which the bridge is reached from Thawar descends the scarped face of the precipice by a succession of ladders.
From the boiling-point of water I estimated the elevation of the bridge, which was more than a hundred feet above the river, at 6200 feet. This would indicate a fall of about 1000 feet since leaving Iskardo, or, as the river flows very tranquilly till it leaves the Iskardo plain, from the commencement of Rondu, a distance by the road of twenty-nine miles, but not, I should think, more than twenty along the course of the river, as the road winds very much in crossing ridges. This is equivalent to a fall of about fifty feet per mile, which, for a stream discharging so vast a volume of water, is very considerable indeed, but not more than is indicated by the general turbulent course of the river.
CULTIVATED TREES.
March, 1848.
The villages of Rondu, though mostly small, have abundance of fruit-trees. The apricot is still the commonest of these; but there are also many fine walnuts, and plenty of vines climbing up the trees, and remarkable for the great size of their trunks. Willows are very common, and two kinds of poplar, and now and then there occurs a plane-tree of enormous girth and stature, which must, no doubt, afford a most welcome shade from the rays of the too-powerful sun of summer, the heat of which, in so deep and rocky a ravine, must be very oppressive. The willow and poplar had already begun to show signs of vitality, the flower-buds being almost ready to expand; the other trees seemed still quite inert.
All over the hills of Rondu the juniper[16] is rather common, and seemingly quite at home both on the higher ridges, and in the bottom of the ravine close to the river. It forms generally a low bush, but occasionally I saw small trees, and once, in a level tract close to the river and near a village, a considerable tree perhaps forty feet high. The young plants had made considerable shoots, and were covered with longish acicular patent leaves, very different from the short adpressed scaly leaves of the adult plant.
PINE TREES.
March, 1848.
Rondu is remarkable for producing another Coniferous tree, indeed a true pine, namely, Pinus excelsa, which occurs in small groves in several places on the south side of the river, at elevations from eight to ten thousand feet above the sea. It was first observed opposite the village of Siri, but is more plentiful above the fort of Rondu. One or two trees occur close to the river, and on the north side, so that I was enabled to get specimens and ascertain the species. The occurrence of this tree must be considered to indicate a greater degree of humidity than exists in the upper parts of the Indus valley, so that Rondu is the place of transition between the Tibetan climate and that of the eastern Punjab, into which the Indus passes at its point of exit from the mountains.
The mountains of Rondu contain much granite, which occurs in great mass at the bridge opposite the fort. In this place the granite occupies the lower part of the ravine, close to the river, while the higher parts of the mountains are composed of gneiss or clay-slate, sometimes passing into sandstone, or of a highly crystalline magnesian rock. The granite consists chiefly of quartz and mica, the former, as well as the felspar, white, the mica black and highly crystalline. The stratified rocks are always highly metamorphic, and are shattered and dislocated by the intrusion of the granite to a very great extent.
LOWER PART OF RONDU.
March, 1848.
Below Thawar and the fort of Rondu, the valley of the Indus continues extremely narrow and difficult, and ceases to be inhabited at the village and fortified post of Tok, at which place a few soldiers are stationed, to keep up the communication with Gilgit, and to give notice of any incursions from that side. Thence, as far as the mountain range which bounds the Gilgit valley on the east, the valley is said to be quite desert. The disturbed state of Gilgit had made me abandon my original intention of continuing my journey in that direction; I therefore made only one march to the westward of Thawar, and found the ravine, along which the river flowed, so barren and uninteresting, that I did not consider it necessary to visit Tok, but retraced my steps towards Iskardo, which I reached on the 11th of March.