The Meaning of Relativity / Four lectures delivered at Princeton University, May, 1921

by Albert Einstein

) be a contra-variant vector whose components are given with respect to the co-ordinate system of the

. Let

and

be two infinitesimally near points of the continuum. For the infinitesimal region surrounding the point

, there is, according to our way of considering the matter, a co-ordinate system of the