The population of China has never been exactly ascertained. It has been variously estimated by foreign travellers, Sacharoff, in 1842, placing the figure at over four hundred millions. The latest census, taken in 1902, is said to yield a total of four hundred and ten millions. Perhaps three hundred millions would be a juster estimate; even that would absorb no less than one-fifth of the human race. From this total it is easy to calculate that if the Chinese people were to walk past a given point in single file, the procession would never end; long before the last of the three hundred millions had passed by, a new generation would have sprung up to continue the neverending line. The census, however, is a very old institution with the Chinese; and we learn that in A.D. 156 the total population of the China of those days was returned as a little over fifty millions. In more modern times, the process of taking the census consists in serving out house-tickets to the head of every household, who is responsible for a proper return of all the inmates; but as there is no fixed day for which these tickets are returnable, the results are approximate rather than exact.