This revolution is called the Eulerian motion, after the mathematician who discovered it.
In the Eulerian method the attention is fixed on a particular point of space, and the change is observed there of pressure, density and velocity, which takes place during the motion; but in the Lagrangian method we follow up a particle of fluid and observe how it changes.
The Eulerian Form of the Equations of Motion.
Were these currents invariable their only effect would be that the Eulerian motion would not take place exactly round the mean pole of figure, but round a point slightly separated from it.
The phenomenon is known as the Eulerian nutalion, since it is supposed to come under the free rotations first discussed by Euler.
Two methods are employed in hydrodynamics, called the Eulerian and Lagrangian, although both are due originally to Leonhard Euler.
The Lagrangian method being employed rarely, we shall confine ourselves to the Eulerian treatment.
The remainder of the first volume relates to the Eulerian integrals and to quadratures.
The latter portion of the second volume of the Traite des fonctions elliptiques (1826) is also devoted to the Eulerian integrals, the table being reproduced.
Newcomb's explanation of the lengthening of the Eulerian period is found in the Monthly Notices of the Royal Astronomical Society for March 1892.