<p>Few climbs are awarded the honour of being reduced to their initials. CB, the Central Buttress of Scafell, considered for years to be the hardest climb in the British Isles, is one of them. 'Have any of you ever noticed a bayonet-shaped crack descending from the skyline about midway between Moss Ghyll and Botterill's Crack on Scawfell? No? Has it never occurred to you that between these two climbs there is a stretch of nearly two hundred feet ...