166 SYLVICULTURE IN THE TROPICS n .n 



In the "equilateral triangle" pattern, the distance d 

 between the spots in the lines will be equal to the sides 

 of the triangles, while the distance D between the 

 lines will be equal to the height of these triangles, 

 that is, it will be equal to d sin 60 = 0S66d or, say, 

 0'8 7d. Here, as in every other line, the first spot is 

 at half the length of the side of a triangle farther 

 along its line than the preceding ; the calculation may 

 vary according to whether the number of spots in each 

 line is equal or whether there is one less in each 

 alternate line, but for all purposes the following formula 

 will suffice : 



LW 1 L+W 



^~0-87rf 2 + 2 d 



The annexed two tables give the number of planting 

 spots calculated, according to the metric system, for 

 one hectare, and by the English measurement for 

 one acre : l 



1 The second table is copied from the Manual of Indian Sylviculture, by 

 E. E. Fernandez, p. 299. 



[Table 



