AT a meeting of the Geographical Society on Monday evening Capt. T. H. Holdich, R.E., of the Survey of India, read a very interesting paper on the geographical results of the Afghan campaign, in which, after giving a sketch of the features of the country, he summed up the additions lately made to our knowledge. These are very considerable, for in the last two or three years he and Major Woodthorpe with their staff have surveyed and mapped from 25,000 to 30,000 square miles of country. Some of the more important facts ascertained are the facility with which practicable roads can be made through the passes of Afghanistan, and the comparatively low elevation of those of the Hindu Kush, which, according to Capt. Holdich's view, would offer no real barrier to the advance of a properly-equipped army. Capt. Holdich hinted that the further mapping and survey of the country were being continued by native explorers attached to the Survey of India, and he thought that in a few years' time it would be known from end to end, and that our surveys would then join on to those of the Russians north of the Hindu Kush. Capt. Holdich remarked also on the curious intermingling of races in some parts of Afghanistan, and in the ensuing discussion Mr. Blanford, late Director of the Geological Survey of India, made some valuable observations on certain points connected with soil-formation, &c., in Central Asia.