Curvature lines of a transversal eq\'uiaffine vector field along a surface in $3$-space

In this paper we discuss the behavior of the curvature lines of a transversal eq\"uiaffine vector field along a surface in $3$-space at isolated umbilical points.
Comment: 12 pages. This article was originally part of earlier versions of arXiv: 1811.07331 arXiv admin note: text overlap with arXiv:1811.07331