Some More Geodesy Classics From Republican France

  I found a few more works on geodesy from about the time of the French Revolution. You may need to study the Republican Calendar to make sense of the dates which seems somewhat bizarre now. The three books by Mechain & Delambre form the basis for the definition of the meter.

GEODESY

1787 Legendre,
  Mémoire sur les Opérations trigonométriques,
  dont les résultats dépendent de la figure de la Terre

1799 (AN VII) Delambre & Legendre,
  Methodes analytiques pour la determination d'un arc du meridien

1799 Legendre,
  Methode pour determiner la longueur exacte du quart du Meridien

1806 Mechain & Delambre, Base du systeme metrique decimal Vol. 1

1807 Mechain & Delambre, Base du systeme metrique decimal Vol. 2

1810 Mechain & Delambre, Base du systeme metrique decimal Vol. 3

Calentrier republicain

CALCULUS OF VARIATIONS

1805 Legendre,
  Nouvelles méthodes pour la détermination des orbites des comètes

1809 Gauss,
  Theoria motus corporum coelestium in sectionibus conicis solem ambientium

The last two books are cited as the first publications on the use of least squares to minimize errors. There is some controversy over priority since Legendre published first but Gauss claims to have used the method in 1795.