664 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1912. 



has been the principal cause for the creation of outskirts and suburbs 

 of an extensive character. Density of population is generally 

 greater in the center than on the outskirts, but as the dwellings and 

 the lands are more valuable there, an inverse movement has begun, 

 encouraged, too, by hygiene, for the air is better at the boundary 

 than at the city center. 



The direction of extension depends chiefly on geographic and 

 economic conditions, and cities spread out much more rapidly 

 when these conditions are favorable. Bound between natural 

 insurmountable obstacles, the sea or rivers, cities push skyward, 

 as in New York,^ where one sees buildings erected from 30 to 40 

 stories high. But if there are no constraints for looking in any 

 other direction for space needed for their development the advance 

 is preferably toward the west. The prevailing direction of winds 

 from the west, driving back unhealthy odors toward the east, render 

 westerly sections more healthy. Paris and London offer examples 

 of this phenomenon. The pubhc square is no longer the stage for 

 enacting the leading scenes of public life; its role is to relieve 

 monotony, to provide more air and light. The market square 

 still exists, but it tends more and more to be replaced by closed 

 markets. They are hardly anythmg else in the south of Europe, 

 especially m Italy, where the squares still conform to the old type. 

 According to M. C. Sitte, experience shows that the minimum dimen- 

 sion of a public square should be equal to the height, and its maxi- 

 mum should not exceed double the height of the principal edifice, 

 but there must equally be taken into account the width of the 

 adjoming streets.^ 



THE STREET. 



Streets are sometimes so narrow and lateral, roads so few, that 

 the way becomes a closed place, very agreeable to the esthetic eye. 

 Their winding constantly shuts out the perspective, and at each 

 instant presents a new horizon. The straight street prevails to-day, 

 particularly in new cities, such as those in America, where the streets 

 cross at right angles, so as to form a regular draught board. The 

 effect produced depends on the proper proportion between the 

 width of the street and the height of the buildings, and also on the 

 architecture of the structures. 



OPEN SPACES AND GRASS PLOTS. 



Hygiene is more and more occupying the attention of munici- 

 palities of large cities. One notes that m Paris, for example, the 

 mortality from tuberculosis dimmishes in proportion to the extent 



> Compare Pierre Clerget. Villes et ^coles ani<''ricaines. Revue de Fribourg, March-April, 1906. 



sCamillo Sitte, L'art de Mtir les villes. Translation and adaptation by C. Martin, Geneva. Emilfl 

 Magne, L'esthetique des villes. Paris, Mercure de France, 1908. K. Kahn, L'estnetiquedelarue. Paris, 

 Fasquelle, 1901. 



