Page:Popular Science Monthly Volume 21.djvu/405

Rh highway. Some cities are free to extend over the plain in any direction, while others are restricted to narrow valleys, or to islands of which they cover the whole. The city of Cadiz, confined upon an island, has very high houses, with terraces and lookouts, the object being to reach a height where the air will be healthy and the rain-water pure. St. Malo is built much after the same fashion, and the



streets in both cities are very narrow. Every one knows that the principal highways in Venice are canals, and that the several islands are traversed by prodigiously narrow and crooked streets. On the other hand, the cities of Hungary extend over considerable spaces and are thinly populated. The city of Maria Theresa, or Szabadka, for instance, according to E. Keclus, covers a space of eight hundred and ninety-six square kilometres, and is really nothing but a province cut up by regular avenues, by the side of which houses stand at intervals—an oasis of stone in the immense plain.

We may remark, with respect to the bearing of climate, that narrow and crooked streets protect the inhabitants against heat and against cold, but they foster the accumulation of miasms and prevent the circulation of air. Cities tend to expand on the side from which the prevailing winds come. x It is the most pleasant side, because it is free from the unhealthy emanations of the town.