Although Cassini de Thury had surveyed almost exactly this in 1740, it was the invention of the Borda repeating circle which made the Academy confident that a new much more accurate measurement could be achieved.
Kahit Cassini de Thury had ipasukat halos eksakto ito sa 1740, ito ay ang paglikha ng Borda paulit-ulit na bilog na kung saan ginawa ang Academy na ang isang bagong mas tumpak na sukat ay maaaring makakamtan.