Ben Nevis the summit only to find "fragments of earthen and glass ware, chicken bones, corks, and bits of paper". It was not until 1847 that Ben Nevis was confirmed by the Ordnance Survey as the highest mountain in Britain and Ireland, ahead of its rival Ben Macdhui. The summit observatory was built in the summer of 1883, and would remain in operation for 21 years. The first path to the summit was built at the same time as the observatory and was designed to allow ponies to carry up supplies, with a maximum gradient of one in five. The opening of
Crabs of the British Isles Crabs of the British Isles Around 65 species of crab occur in the waters of the British Isles. All are marine, with the exception of the introduced Chinese mitten crab, "Eriocheir sinensis", which occurs in fresh and brackish water. They range in size from the deep-water species "Paromola cuvieri", which can reach a claw span of , to the pea crab, which is only wide and lives inside mussel shells. Several species of wild crab are the subject of crab fisheries around the coasts of the British Isles. The most important are the brown crab or edible crab, "Cancer pagurus"