of the following form: From this table, the field is to be plotted, or protracted. Alternative plotting method: An alternative way to plot the area in Figure 2 is to use several angles and only a few measurements and calculate their positions. This could be done by starting at the center point in Figure 2 which is not labeled, but which will be referred to as "Center." Assume each point can be seen from each other point. From the "center" point, sight and record the angle to each point using the sights as described above. Then move to, and measure the distance to, one of the other points referenced, such as point B. At point B, measure the angles to all the other points. Then, move to an additional point such as point F. Again, measure the distance from the center to the point chosen (F). At that point, measure and record the angles to each of the other points as was done at point B. Chose a scale (a ratio between the size of the area to be plotted and the size of the paper on which you will draw the plot) that will allow the plot to fit on your paper and plot the angles and distances. The advantage of this method over the first one above is that there are fewer distance measurements and any errors in angles or distances will not be cumulative; that is, if you use the first survey method, any angle that is slightly off will distort the remainder of the plot. The second method can also be used when it is not possible to measure some of the distances, for example, if there is a water barrier between two of the points. Also, if there are any inaccuracies in the measurements, they will be revealed in the plot because the points plotted from various angles will not coincide. Additional considerations include the number of times the circumferentor must be set up and aligned. With the first method, the instrument must be set up at each point with a compass. With the second method, the initial set up is at "center." After that, for example at point B, the instrument can be set up by aligning the sight with the reciprocal of the angle between "center" and B. Thus, any local change in the magnetic field that would affect the compass would be