practical hygiene has been
overlooked. Thus one finds here numberless models of dwelling-houses,
showing details of lighting, heating, and ventilation; models not
merely of individual dwellings, but also of school-buildings, hospitals,
asylums, and even prisons. Sometimes the models represent merely
ideal buildings, but more generally they reproduce in miniature actual
habitations. In the case of the public buildings, the model
usually includes not merely the structures themselves but the
surroundings--lawns, drives, trees, out-buildings--so that one can get a
very good idea of the more important hospitals, asylums, and prisons of
Germany by making a tour of the Museum of Hygiene. Regarding the details
of structure, one can actually gain a fuller knowledge in many cases
than he could obtain by actual visits to the original institutions
themselves.

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 Ber