APPROPRIATE INTENSITY OF THE USE OF LAND 27 



That considerable areas near the heart of the city should be very inten- 

 sively used for tenements and apartments is natural and probably inevitable. 

 The demand for housing is naturally greatest in the most favorable locations. 

 Were it not for the ability to multiply housing area by placing one dwelling 

 on top of another, rents would be prohibitive in these favored locations for 

 practically all of those who now occupy apartments or flats. It is natural that 

 the intensity of the demand for housing should vary in the different parts 

 of a given city, the general tendency being, starting with the highest intensity 

 of demand near the center, for this demand to fall rapidly toward the 

 periphery of the city. 



Beyond the central zone of the more intensive housing, the provision 

 of light, air and open space, may be rapidly increased. Radiating from the 

 common business center, the amount of land available for development 

 rapidly increases. When it is necessary to use a rapid transit line to get 

 to the business center a few minutes more or less on the train is unim- 

 portant. Beyond this central housing zone, therefore, regulations requiring 

 much more adequate courts, yards and open spaces, may properly be 

 required. 



The assumption that an individual owner in a city should have un- 

 limited liberty to cover his entire lot to any height is incompatible either 

 with the interests of owners generally or with that of the public. It is not 

 possible to secure the light and air that is essential both to the profitable 

 use of land and to the health and comfort of the public unless the height 

 and area covered by buildings is limited. As Professor Whipple has well 

 stated : " While in general rights in the use of land are bounded by vertical 

 planes, it must not be forgotten that the sun's rays fall slantingly upon 

 the land while the wind movements are chiefly horizontal. These natural 

 elements are interfered with by excessively high and crowded buildings, 

 hence there are rights in land ownership which extend beyond the vertical 

 planes." In a memorandum submitted to the Commission, Professor Whip- 

 ple discusses the importance of light and air in part as follows : 



" Considered from the standpoint of light the sun's rays pro- 

 foundly affect the lighting of rooms. This is a matter of common 

 knowledge, but quantitative relations have been shown by many 

 photometer tests made at points located at different distances from 

 windows, and by similar tests made at the windows of different stories 

 in tall buildings the exterior lighting of which is influenced by ad- 

 joining buildings. Sunlight likewise causes movements of the air. 

 This is due to unequal heating in different places. The air currents 

 thus set up are gentle and desirable. Places which never see the 

 sunlight are more likely than others to contain stagnant air. The sun's 

 rays have a marked disinfecting action and prevent the growth of 

 molds and fungi, thereby eliminating odors of certain kinds. They 

 also destroy bacterial life, whether the bacteria are floating in the 

 air or are attached to the exposed surfaces of pavements, floors or 



