We note that in the first equation, corresponding to the first mesh, the coefficient of the first current is the sum of the resistances in the first mesh, and the coefficient of any other mesh current is the negative of the resistance common to that mesh and the first mesh. The right member of the first equation is the algebraic sum of the voltage source driving the first mesh current in its assumed direction. Replacing the word first by the world second everywhere it appears in these last two sentences will describe the second equation, and so on. This shortcut procedure is a consequence of selecting all the mesh currents in the same direction (clockwise in Fig. 4.13) and writing KVL as the mesh are traversed in the directions of the currents Of course, the method applies only when no sources are present except independent voltage sources.