Preparation of the tablet to work

After selecting a magnification on the left side of the slider is constructed with a pencil linear scale. But distance shooting is measured not only on the eye (in meters), but steps should therefore be to build and scale of the pairs of steps (the surveyor must know in advance the value of its steps). On this basis, and construct a scale of steps. Existing millimeter division facilitate and accelerate its plotting. Prepared in this way the slider is completely replaces the compass at postponing the distance (a pencil with celluloid strips easily washed clean with a damp cloth). Once the line of the slider put back in place, the tablet is ready to work.