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Barograph

001

A barometer measures the atmospheric pressure or the pressure in the air. The atmospheric pressure is the weight of a column of air from where the barometer is and up to the top of the atmosphere. The higher up you get, the lower the pressure. The pressure in the air decreases with altitude. The weather conditions affect the measuring, but as a principle we can say that the barometric pressure diminishes with 1 hecto Pascal (hPa) per 8 meters. That is to say: If you live 80 meters above sea level, the pressure will be 10 hPa lower than at sea level. There are different types of barometers: mercury barometers, water barometers and aneroid barometers (no fluid), big ones and pocket versions etc. A barograph is an instrument that transfers the measuring of the atmospheric pressure from a barometer to a roll of paper. On this paper you could then read the air pressure over time. The Fram Museum’s barograph is made by Richard Frères in Paris and was made in the 1890s. When Roald Amundsen and the other participants on the South Pole expedition in 1911 needed to find their height above sea level (altitude), they had to know the atmospheric pressure. That is why they brought both small and big barometers in addition to the tables and almanacs necessary for their calculations. Amundsen brought furthermore a hypsometer to find the atmospheric pressure. This is an instrument that measures the boiling point of a fluid, for instance water. Water and other fluids boil at lower temperatures when the air pressure decreases, and therefore the hypsometer will indicate what the pressure is at a given place and with that indicate the actual height above sea level. “The boiling this evening gave 9 200 feet,” says Amundsen in his diary on the 27th of November 1911. Two weeks after this he is wondering if Shackleton on his Nimrod Expedition 1907-09 could have carried any hypsometer at all on his way to the Pole where he reached 88⁰S: “And now the hypsometer this evening shows t

Theodolite

009

The Fram Museum has several theodolites from the end of the nineteenth century and the beginning of the twentieth. This one has the inscription: C. H. G. Olsen, Christiania, nr. 2. Cartographers, surveyors and different engineers use them to find the specific topography of a certain location. A theodolite is an instrument that measures horizontal and vertical angles. In its form it consists of a telescope mounted to swivel both horizontally and vertically. After the telescope is adjusted precisely, the two accompanying scales, the vertical one and the horizontal one, are read. The Fram theodolites were indispensable instruments during the great period of discoveries in the Polar Regions. On board the Fram, it was an essential part of the scientific equipment. During the second Fram Expedition in the years 1898-1902, more than 150 000 square kilometres of new land was mapped. The participants went on extraordinary long sledge journeys to make maps - some of these were more than 1000 kilometres long. The traditional theodolites are today replaced by electronic ones, so called total stations, and different forms of laser instruments. Reading is done electronically, and not with a microscope as in the old days. Cartography and surveying are sciences and activities that aim at making maps or profiles of an area on the surface of the Earth. Contemporary surveying is mostly carried out with the use of GPS and the mentioned total stations. GPS stands for ‘global positioning system’.

"Victory awaits him, who has everything in order - luck we call it.  Defeat is definitely due for him, who has neglected to take the necessary precautions - bad luck we call it"

Roald Amundsen

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