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
Ben Nevis to reproduce these phenomena in the laboratory, resulting in his invention of the cloud chamber, used to detect ionising radiation. Marjory Roy, a member of the Scottish Meteorological Society is the author of the book "The Ben Nevis Weathermen", which is in print and available from SMC or from the West Highland Museum in Fort William. This tells the story of the funding, building and operating of the Ben Nevis Observatory in Fort William, Scotland. Ben Nevis's popularity, climate and complex topography contribute to a high number of mountain rescue incidents. In 1999, for example, there were 41 rescues and