Tryggve Rubin, Swedish geodecist, was a member of the Swedish-Russian expedition for measuring the Spitzbergen arc of meridian in the summer of 1901 and was the leader of the expedition that completed the work during the next summer. His doctoral thesis, Le r?seau de la base su?doise au Spitzberger (The grid from the Swedish base to Spitzbergen) was published at Upsala in 1903.
Dr David Gill* of the Royal Observatory, Cape of Good Hope, who supervised the geodetic survey of southern Africa, including the measurement of a geodetic arc along the 30? E meridian, selected Rubin as officer in charge of the geodetic survey of Northern Rhodesia (now Zambia). Rubin's task would be to extend the geodetic survey carried out by Alexander Simms* in Zimbabwe, northwards to the shores of Lake Tanganyika. He arrived at the Cape early in April 1903 and after spending three weeks at the Royal Observatory he and Dr F.O. St?hr*, surgeon of the expedition, sailed for Chinde, on the Mozambique coast. They reached Feira, on the Zambezi near the border between Zambia and Mozambique, on 13 July. In October 1903 Rubin was joined by his chief assistant, G. Tyrell McCaw*. They had to take measurements at several points south of the Zambezi, and re-select some others because further reconnaissance had shown them to be unsuitable for extending the survey northwards. Like Simms, Rubin's party found extraordinary difficulties presented by haze, smoke, heavy rains, dense vegetation, and lack of roads. Furthermore, during the first year much of their time was devoted to work connected with the boundary between the British territories and Mozambique. Rubin extended the geodetic chain northwards for almost 800 km, from Manyangau (latitude 16? 25' 45" S) in Zimbabwe to Mpange Hill (latitude 9? 40' 57" S) in the north of Zambia. This triangulation included 35 geodetic stations. Latitude was measured at 18 of these, and an astronomical azimuth at two of them. A baseline some 17 km long was measured with invar wires near the Zambezi. As a result of financial constraints the Board of the Chartered Company (which administered the territory at the time) ended the survey in June 1906. However, Rubin continued his work on the last few beacons for another six months during leave due to him. An account of the survey was published many years later by the British War Office as Report on the measurement of the arc of the thirtieth meridian in North-eastern Rhodesia executed by Dr T. Rubin, under the direction of Sir David Gill (London, 1933). The report was also issued as Volume 6 of The geodetic survey of South Africa (London, 1933) under the names of D. Gill and T. Rubin.