Rossbank Observatory celebrates the opening of the meteorological observatory on the Domain in Hobart, Tasmania. The painting shows three main figures in the centre: Lieutenant-Governor Sir John Franklin, the explorer Captain James Clarke Ross, and his second-in-command, Captain F R M Crozier. Lieutenant Joseph Henry Kay, Director of the Observatory, is on the left. The observatory was part of an international data gathering organisation, the Magnetic Union (Magnetische Verein) based in Göttingen, Germany. Observatories across the world collaborated on collecting data on the strength of the Earth’s magnetic field. For nearly eight years, Kay, with his assistants, recorded hourly readings from the magnetic and meteorological instruments housed at the Observatory.
It was in the eleventh century that the Chinese discovered that the mineral lodestone would naturally point north-south if suspended. This discovery had led to the development of compasses that allowed explorers to plan and navigate with much greater confidence. Navigating by compass was not foolproof though as the farther polewards that you travel, the more erratic compasses become. For nations dependent upon shipping for their trade and security this had serious consequences. Greater understanding of how the planet’s magnetism worked was essential.
On 5 October 1839, Ross led an expedition to find the South Magnetic Pole. He was a highly experienced navigator and had already successfully located the North Magnetic Pole in 1831. The British Royal Navy provided Ross with two heavily reinforced bomb ships, the Erebus and Terror, thought to be well equipped for facing sea ice. Arriving in Hobart in August 1840, Ross learnt to his dismay that two other expeditions, one French led by Dumont d’Urville, and the other American led by Wilkes, had already spent two seasons unsuccessfully searching for the Pole. Determined to take a different route, Ross struck out due south, traveling at times through heavy pack ice until finally breaking into open water. He had discovered the Ross Sea, and was tantalisingly close to the South Magnetic Pole.
Taking measurements from his ship, Ross was disappointed to discover the Pole lay eight hundred kilometres inland to the southwest. Hoping that he might yet find an ocean route Ross continued south along the mountainous coastline. After sixteen days travel his route was once more blocked, this time by ‘a fine volcano spouting fire and smoke’. The expedition had stumbled across the southernmost active volcano, which Ross named Mount Erebus. Continuing out to the east, a low white line seemed to stretch as far as the eye could see. Drawing closer the sailors were astonished to discover a perpendicular cliff of ice soaring between forty and sixty metres above the sea, seemingly perfectly flat and level at the top. Recording the icy cliff on his charts as a Great Ice Barrier (now known as the Ross Ice Shelf), their hopes of reaching the Pole were dashed. After sailing a further 720 kilometres eastward without discovering any way beyond, Ross turned his vessels north for Hobart.
Currently on display at the Tasmanian Museum and Art Gallery