In this map all places where Christians resided, where there were Christian congregations, churches, preaching places, schools, hospitals, dispensaries, etc., would be marked.

It would be a pictorial presentation of the facts so far as they were capable of expression in map form.
But whether in map form or in statistical form, the area and the population for which the mission is working must be expressed either by exact figures or by estimates if we are to trace progress.
If these tables were kept over a number of years, the missionaries on the spot and directors and inquirers at home would be able to see what progress was being made towards fulfilling the obligation implied by the definition of the station area or district, and what that obligation involved.
II.

When we know the work to be done we turn to the consideration of the force available.

This force consists of permanent and more or less temporary members.

Some will in all human probability remain in the place till they die; they are of it, they belong to it; others will probably depart elsewhere; they are not of the place; they speak of home as far away; they are liable to removal; sickness which does not kill them takes them away; the call of friends or business carries them back to their own land; they are strangers all their days in the mission district.