But, unfortunately, these first facts which we have desired are, like
other facts of importance, procured only with difficulty and toil. In
order to fill up the preceding tables the missionary surveyor must be
able to state what is the area and what the population in the station
district. But some could not supply that information. Its acquisition
might involve a journey of many months given up to careful examination
and inquiry. It is no small demand to make. In many cases a reasoned
estimate is indeed the only possible statement; but as we have already
argued careful estimates are invaluable, and where a census does not
exist they give us for the time something to work upon.

Where the physical survey can be undertaken it is most illuminating
work, illuminating both to the missionaries and to their native helpers,
who often gain an entirely new view of their work and its possibilities
from such personal examination. Testimony to the value of this
experience is growing daily in weight and volume.

This physical survey would naturally result in the production of a map
of the area in which the cities, towns, and villages in the station
district were marked with notes on their character from the missionary
point of view. 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.