The banks of the river are very high, so that the enormous accession which the volume of water receives during inundation scarcely affects the breadth, but merely increases the depth. The rock forming the banks is of a dark-coloured slate, polished by the force of the stream, so as to shine like black marble. Between these, "one clear blue stream shot past." The depth of the Indus here is thirty feet in the lowest state, and between sixty and seventy in the highest, and runs at the rate of six miles an hour. There is a ford at some distance above the confluence of the river of Khabool; but the extreme coldness and rapidity of the water render it at all times very dangerous, and on the slightest inundation quite impracticable. The bridge is supported by an association of boatmen, who receive the revenue of a village allotted for this purpose by the Emperor Akbar, and a small daily pay as long as the bridge stands, and also levy a toll on all passengers. On the right bank, opposite Attock, is Khyrabad--a fort built, according to some, by the Emperor Akbar, according to others by Nadir Shah. This locality is, in a military and commercial point of view, of much importance, as the Indus is here crossed by the great route which, proceeding from Khabool eastward through the Khyber Pass into the Punjaub, forms the main line of communication between Affghanistan and Northern India. The river was here repeatedly crossed by the British armies, during the late military operations in Affghanistan; and here, according to the general opinion, Alexander, subsequently Timur, the Tartar conqueror, and, still later, Nadir Shah, crossed; but there is much uncertainty on these points. [Illustration: THE FORT OF ATTOCK.] The fortress was erected by the Emperor Akbar, in 1581 to command the passage; but, though strongly built of stone on the high and steep bank of the river, it could offer no effectual resistance to a regular attack, being commanded by the neighbouring heights. Its form is that of a parallelogram: it is 800 yards long and 400 wide. The population of the town, which is inclosed within the walls of the fort, is estimated at 2000. * * * * * THE ORDER OF NATURE. [Illustration: Letter S.] See through this air, this ocean, and this earth, All matter quick, and bursting into birth. Above, how high progressive life may go! Around, how wide! how deep extend below! Vast chain of Being! which from God began, Natures ethereal, human, angel, man, Beast, bird, fish, insect, what no eye can see No glass can reach; from Infinity to thee From thee to Nothing.--On superior pow'rs Were we to press, inferior might on ours; Or in the full creation leave a void, Where one step broken the great scale's destroyed From Nature's chain whatever link you strike, Tenth or ten-thousandth, breaks the chain alike.