of
previous armies. At the same time the conditions under which such a
survey was to be made were exactly the same as those under which the
rough reconnaissances of the former campaign were obtained. The
surveyor was under the same urgent restrictions, both as to time and as
to the limits of his own movements off the direct line of march.
McNair, with one or two others, was selected for this topographical
duty with the Afghan field force, and right good use he made of his
opportunities. He was present during the fighting which took place
before Kabul in the winter of 1879-80, and was shut up with the
garrison of Sherpur during the fortnight's siege. His energy and
determination carried him through the campaign with more than
credit--he was able to illustrate modern methods of field topography in
a manner which threw new light on what was then but a tentative and
undeveloped system. He was one of the first to prove the full value of
the plane-table in such work as this, for it must be remembered that he
was working in a country peculiarly favourable to the application of a
system of graphic triangulation, and very different to the densely
forest-clad mountains of the eastern frontier into which the
plane-table had been carried before, with advancing brigades. At the
close of the war, which brought no recognition of his exceptional
services, he was appointed to the Kohat survey party, which was
primarily raised for the mapping of the Kohat district, but which
afforded occasional opportunities for extending topography across the
border. When this party was first raised our frontier maps were of the
most elementary character; there was many a wide blank in the
topography of the lower borderland, and geographical darkness shrouded
nearly the whole line of frontier mountains. The hostility of the
border people had always been such that it was a matter of considerable
risk to approach them, but the temper of the tribes was then rapidly
changing with the times, and McNair rapidly succeeded in establishing
himself on a friendly footing with frontier robber chiefs, whose
assistance was invaluable in arranging short excursions across the
line, by means of which he was able to complete a fairly accurate map
of most of the border country. No work that ever he accomplished has
been of more value to the Government of India than this unobtrusive
frontier mapping. It was whilst he was thus occupied between Peshawur
and Dera Ismail Khan