The International Association of Geodesy is a constituent association of the International Union of Geodesy and Geophysics focusing on the science which measures and describes the Earth's shape, its r
West Europe–Africa Meridian-arc: a meridian arc extending from the Shetland Islands, through Great Britain, France and Spain to El Aghuat in Algeria, whose parameters were calculated from surveys carried out in the mid to late 19th century. It yielded a value for the equatorial radius of the earth a = 6 377 935 metres, the ellipticity being assumed as 1/299.15. The radius of curvature of this arc is not uniform, being, in the mean, about 600 metres greater in the northern than in the southern part.
Gravimeter with variant of Repsold-Bessel pendulum
The arc measurement of Delambre and Méchain was a geodetic survey carried out by Jean-Baptiste Delambre and Pierre Méchain in 1792–1798 to measure an arc section of the Paris meridian between Dunkirk
The Panthéon in Paris. At the time of Jean-Baptiste Joseph Delambre, it served as a warehouse for all the old weights and measures which had been sent by towns throughout France in anticipation of the standardisation of weights and measures by the establishment of the new decimal metric system.
The triangulation mesh of the Anglo-French Survey (1784–1790).
Repeating circle devised by Jean-Charles de Borda and constructed by Étienne Lenoir
The free-standing belfry in Dunkirk on the French English Channel coast – the northerly end of the meridian survey of 1792–9