4 SHADE-TREES IN TOWNS AND CITIES 



furnishes the conditions and forces by which the other 

 maintains life and health. Trees also help to modify the 

 temperature of our streets, and add to the comfort of the 

 residents. The normal heat of summer is still further 

 intensified in cities by the reflections from the pavements 

 and the buildings. Besides cutting off the direct and the 

 reflected rays of the sun, foliage exercises a marked effect 

 on the temperature by evaporating large quantities of 

 water from its surface, and the reduction of the temper- 

 ature so resulting is greatest on dry, hot days when relief 

 is much needed. 



The appraisal of the tree as a sanitary factor in the life 

 of the city was confirmed by the Commissioner of Health of 

 the city of New York, who, in 1872, reported on the causes 

 of the high death-rate during the summer months in the 

 city of New York. The chief cause was determined to be 

 the excessive heat which characterized those months. 1 It 

 was recommended in the report to the Board of Health that 

 legislation be secured empowering and requiring the De- 

 partment of Parks to plant and cultivate trees in all of the 

 streets, avenues, and public places in the city. The value of 

 trees to the health of a city was further emphasized by the 

 passage of the following resolution by the New York County 

 Medical Society : 



"Resolved, that one of the most effective means for miti- 

 gating the intense heat of the summer months and diminish- 

 ing the death-rate among children is the cultivation of an 

 adequate number of trees in the streets. ' ' 



The economic value of shade-trees is inestimable. They 

 add to the value of real estate, and are among the first 



'"Vegetation a Remedy for the Summer Heat of Cities," by Stephen 

 Smith, M.D., LL.D., Popular Science Monthly, February, 1899. 



