In 1891, at the meeting of the Permanent Commission of the International Geodetic Association in Florence, Wilhelm Foerster referred to the discovery by Seth Carlo Chandler of the polar motion predicted by Leonhard Euler in 1765 and his impact on the determination latitudes.

He proposed that the International Geodetic Association implement a systematic study of this important phenomenon.

After 1916, the operations of the International Latitudes Service continued under the aegis of the Reduced Geodetic Association among Neutral States presided by Raoul Gautier director of Geneva Observatory.

The data collected by the observatories over the years still has use to scientists, and has been applied to studies of polar motion, the physical properties of the Earth, climatology and satellite tracking and navigation.

The final six observatories were located, in order of Longitude (E to W), in: The ILS was renamed International Polar Motion Service (IPMS) in 1962.