This is probably the first clear exposition which has ever been made of the general nature of the route connecting Kabul with Afghan Turkistan, and for it we must give Lieut. Wood all the credit that is fully due; for no subsequent surveys and investigations have materially altered his opinion. It must not be forgotten that in dealing with the story of Afghan exploration we are touching on past records. The far-sighted policy of public works development, which distinguished the late Amir Abdurrahmon, led to the extension of roads for facilitating commerce between the Oxus and Kabul, the full effect of which we have yet to learn. To the north of Kabul the roads opened to khafila traffic, _via_ the Chahardar Pass and the Khawak, have introduced a new and important feature into the system of Afghan communications; and it is more than probable that the facilities for wheeled traffic between Kabul and Tashkurghan have lately been largely increased.[12] It is well also to remember that it is not the physical difficulties of rough roads and narrow passes which form the chief obstacle to the movement of large bodies of troops. Roads can be made, and crooked places straightened with comparative ease, but altitude, sheer altitude, still remains a formidable barrier, which no modern ingenuity has taught us to overcome. Deep impassable snow-drifts, and the fierce killing blasts of the north-westers of Afghanistan close these highland fields for months together; and neither roads nor railways (still less air-ships) can prevail against them. When Wood and Lord turned eastward from Khulm, and passed on to Kunduz and Badakshan, they were treading ground which was absolutely new to the European explorer, and which has seldom been reached even by the ubiquitous native surveyor. Lord gives us but a scanty account of Kunduz and northern Badakshan in his report, and we must turn to the immortal Wood (the discoverer of one of the Oxus' sources) for fuller and more picturesque detail. Wood left Kunduz for the upper Oxus in the early spring of 1838, and it is somewhat remarkable that he should have effected an important exploration successfully in regions so highly elevated at the worst season of the year. Before following Wood to the Oxus, we may add a few further details of that important march from Kabul to Kunduz.