much studied for a long time back, and is one which marches towards a solution which promises to be perfectly satisfactory in view of the progress already made.  Wide streets have replaced narrow alleys, air circulates freely everywhere, trees and enormous gardens have been planted on every side, and the salubrity of the house is assured by a severe inspection, one which will become yet more severe, it is to be hoped, in the case of those owners who are inclined to despise regulations.  It would be so simple in place of continuing the ancient ways, whose inconveniences are so well demonstrated in the large model of an unhealthy house exhibited in the pavilion of the city of Paris, to adopt all the new systems of sanitation which, on their part, are shown in application in the model of a sanitarily perfect house which has been placed opposite to it.  To establish this comparison two very simple models of construction have been selected, proving that healthfulness is not merely an attribute of luxury, but that the most modest houses can present all possible guaranties from this point of view.  The healthfulness of houses, and consequently of cities, depends amongst other multiple but relatively simple causes on two preeminent conditions,—­that of the removal of excrement, and the purity of the water-supply.  In a large degree the first condition is subordinated to the second.  “Everything to the sewer” is recognized by the most competent hygienists as the best system, but only on the condition that water shall be abundant and that no stagnation of the material shall be allowed.  These problems, which were for a long time studied by M. Durand-Claye, and to which he devoted himself until his premature death unfortunately took him from us, have received the attention of his devoted successors, who have already brought to fruition interesting solutions which prompt us to hope for a completely satisfactory system in the near future.

Three glass reservoirs, containing water from the Seine, from the Ourcq and the Vanne, allow us to perceive the difference of quality which exists between these three sources of supply, the first of which, with its yellow color, is anything but appetizing, and the second is not much less doubtful, while the third, alone, presents the limpidity and transparency which one has a right to demand in potable water.  Nevertheless, one should not believe, as many persons do, that the water that we see in this reservoir, and which has been taken within the limits of Paris, is the same that is distributed from time to time through each quarter.  The water there used is taken up-stream and before it has been soiled by its passage through the suburbs and city.

In the same pavilion the Administration has exhibited the plans and the comparative views of the city taken at different epochs since 1789 up to the last months of 1889.  We here see the march of progress in this immense city, expanding without cessation like a drop of oil, and as it enlarges crossed by great arteries which establish across its mass conduits for aeration, and at the same time suppress the agglomerations of former days.