Two beacons meant revolt or invasion.

We never saw but one beacon.

And ever, as we rode, Vandervoot brought up the rear, wondering, "God in heaven, what now ?" Keijo we found a vast city where all the population, with the exception of the nobles or yang-bans, dressed in the eternal white.

This, Kim explained, was an automatic determination and advertisement of caste.
Thus, at a glance, could one tell, the status of an individual by the degrees of cleanness or of filthiness of his garments.

It stood to reason that a coolie, possessing but the clothes he stood up in, must be extremely dirty.