The $g$'s may be constants or functions of $x_1$, $x_2$. Their value is dependent on the observer's reference system and on the geometrical character of the surface observed. The curves being arbitrary, the formula is appropriate for any reference system, or even if the observer does not know exactly what his reference system is. (The Fabric observer does not know what his space and time partitioning actually is because he is in a gravitational field). It is the $g$'s which disclose the geometry of an observer's partitions, and their values also contain a reflection of the character of the region observed. We find $s$ by direct exploration with a moving ship ($\Omega$ is found by direct exploration with a freely moving particle); $dx_1$, $dx_2$ are the observed length and breadth measurement differences which we have to relate to $s$. By making sufficient observations in a small area and referring them to the general formula we can find the values of the $g$'s for the observer's particular reference system. Different values for $g$'s will be found if the observer changes his reference system, but there is a limitation to the values so obtainable owing to the part played by the surface itself, which is diffidently expressing its intrinsic geometrical character in the $g$'s in each observation. EINSTEIN'S RESULTS Thus we approach the absolute character of the surface through the relative nature of the observer's reference system. There is a relationship common to all values of the $g$'s that belong to the same curvature. This relationship is expressed by a differential equation. It is this equation of curvature that the airship's observer must find. Einstein's problem was similar, but he was concerned with four dimensions, which entailed a general formula with ten $g$'s, and he had to find a set of differential equations of the second order to determine the law of Fabric curvature. He divided the Fabric into regions: I. World-Frame--beyond influence of energy. II. Empty region--free of energy, but under its influence. III. Region containing free energy only. Each region has a characteristic curvature. By means of an absolute differential calculus--a wonderful mathematical scaffolding erected by Riemann, Christoffel and others--involving the theory of tensors, he succeeded in finding such a set of equations. He kept the following points in view: (1) The equations must not only give the character of region II, but must satisfy the special case of region I; (2) They must be independent of any partitioning system, because the General Theory of Relativity demands that a law of nature be in a form appropriate for all observers whatever their position and motion; (3) They must be concerned with energy which is conserved, not mass which the Special Theory showed dependent on velocity. This set of differential equations which shows how the curvature of the Fabric at any point links to the curvature at neighboring points is