The same thing is true of various other features of the subjects represented. Thus there is a very elaborate model here exhibited of the famous Berlin system of sewage-disposal. As is well known, the essential features of this system consist of the drainage of sewage into local reservoirs, from which it is forced by pumps, natural drainage not sufficing, to distant fields, where it is distributed through tile pipes laid in a network about a yard beneath the surface of the soil. The fields themselves, thus rendered fertile by the waste products of the city, are cultivated, and yield a rich harvest of vegetables and grains of every variety suitable to the climate. The visitor to this field sees only rich farms and market-gardens under ordinary process of cultivation. The system of pipes by which the land is fertilized is as fully hidden from his view as are, for example, the tributary sewage-pipes beneath the city pavements. The average visitor to Berlin knows nothing, of course, about one or the other, and goes away, as he came, ignorant of the important fact that Berlin has reached a better solution of the great sewage problem than has been attained by any other large city. Such, at least, is likely to be the case unless the sight-seer chance to pay a visit to the Museum of Hygiene, in which case a few minutes' inspection of the model there will make the matter entirely clear to him. It is to be regretted that the authorities of other large cities do not make special visits to Berlin for this purpose; though it should be added that some of them have done so, and that the Berlin system of "canalization" has been adopted in various places in America. But many others might wisely follow their example, notably the Parisians, whose sewerage system, despite the boasted exhibition canal-sewer, is, like so many other things Parisian, of the most primitive character and a reproach to present-day civilization.