 Carlos Ibáñez e Ibáñez de Ibero and Frutos Saavedra Meneses went to Paris to supervise the production by Brunner of a four metres long measuring instrument which they had devised and which they later compared with Borda's double-toise N°1 which was the main reference for measuring all geodetic bases in France and whose length was 3.8980732 metres.In 1867 at the second General Conference of the International Association of Geodesy (German