LEAF AREA OF TEEES. 495 



1895 studies were made, under my direction, by Messrs. 

 Kirkland and Hylan, upon the leaf area of three average- 

 sized trees, as follows : — 



The dimensions of a medium-sized Baldwin apple tree 

 were carefully measured and the leaves upon one-fourth of 

 the tree counted. The average area of a single leaf was 

 computed by careful measurement of ten average leaves, 

 and the total leaf area ascertained by multiplying the whole 

 number of leaves l)y this last factor. The data concerning 

 the tree are given below : — 



Height of tree, 23 feet. 

 Diameter of top, 23 feet, 9 inches. 

 Diameter of trunk, 1 foot, 5^ inches. 

 Number of leaves, 99,040. 



Average area of single leaf, 30.188 square centimeters. 

 Leaf area of tree, 298.981952 square meters or 3,218.25 square 

 feet. 



A second Baldwin apple tree aiforded data as follows : — 



Height, 18 feet, 5 inches. 

 Diameter of top, 26 feet, 7 inches. 

 Diameter of trunk, 1 foot, 5^ inches. 

 Number of leaves, 108,540. 



Average area of single leaf, 29.294 square centimeters. 

 Leaf area of tree, 317.957076 square meters or 3,422.49 square 

 feet. 



The leaf area of a red oak ( Querciis rubra') was computed 

 with the following result : — 



Height of tree, 41 feet, 6 inches. 



Diameter of top, 37 feet. 



Diameter of trunk, 1 foot, 3 inches. 



Number of leaves, 35,764. 



Average area of single leaf, 83.5705 square centimeters. 



Leaf area of tree, 298.88 square meters or 3,217.16 square feet. 



In the actual spraying of trees the poison mixture should 

 be thoroughly applied to both surfaces of thS leaf; so that, 

 to find the amount of surface necessary to be covered in 

 spraying these trees, the area should be doubled. • 



