BEN NEVIS, the highest mountain in the British Isles, in Inverness-shire, Scotland. It is 4406 ft. above the level of the sea, and is situated 412 m. E.S.E. of Fort William, the meridian of 5° W passing through it. As viewed from Banavie on the Caledonian Canal, it has the appearance of two great masses, one higher than the other, and though its bulk is impressive, its outline is much less striking than that of many other Highland hills. Its summit consists of a plateau 100 acres in area, with a slight slope to the south, terminating on its north-eastern side in a sheer fall of more than 1500 ft. Snow lies in some of the gorges all the year round. The rocks of its lower half are mainly granite and gneiss; its upper half is composed of porphyritic greenstone, and a variety of minerals occur. Its circumference at the base is about 30 m. It may be described as flanked on the west and south by the Glen and Water of Nevis, on the east by the river and Glen of Treig, and on the north by the river and Glen of Spean. From 1881 till 1904 meteorological observations were taken from the summit of Ben Nevis, the observers at first making the ascent daily for the purpose. In 1883, however, an observatory, equipped at a cost of £4000 (raised by public subscription), was opened by Mrs Cameron Campbell of Monzie, who provided the site. The observatory, which was connected by wire with the post office at Fort William, was provisioned by the Scottish Meteorological Society, to whom it belonged. The burden of maintaining it, however, proving too great for the society’s means, appeal was made in vain to government for national support, and the station was closed in 1904. The bridle road up the mountain leaves Glen Nevis at Achintee; it has a gradient nowhere exceeding 1 in 5, and the ascent is commonly effected in two to three hours. There is a small hotel on the summit for the convenience of tourists, especially of those anxious to witness sunrise. From the summit every considerable peak in Scotland is visible. Observations conducted during several months have shown that, whilst the mean temperature at Fort William was 57° F., at the summit of Ben Nevis it was 41° F., and that though the rainfall at the fort amounted to 24 in., it was as much as 43 in. on the top of the Ben.