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.