DUMBER OF PLANTING SPOTS. 287 



The three last terms aggregate just one half the number of 

 planting spots along the perimeter of the entire area. When this 

 area is large, they may, for all practical purposes, be neglected ; 

 but if they are taken into account we may generalise the preceding 

 formula into the following approximate rule : 



When planting according to a rectangular pattern, divide the total 

 area of the (/round in square feet by the product of the two planting 

 distances and half the perimeter in feet by the shorter of these distan- 

 ces ; the sum of the two quotients will be the total number of planting 

 spots to be prepared. 



THE SQUARE PATTERN. Here a = b. Hence the number of 

 planting spots, according to the formula given above, 



= AB + AB_ 



a* a 



and we have the following general rule : 



When planting in squares, divide the total area of the ground in 

 square feet by the square of the planting distance, and half the jieri- 

 meter in feet by that distance ; the sum of the two quotients will very 

 nearly give the total number of planting spots to be prepared. 



In operating over large areas, the value of the two last terms 

 becomes insignificant. 



THE EQUILATERAL TRIANGLE PATTERN. Referring to Fig. 



o o 



100, we see that the distance between the consecutive planting- 

 spots along AD and lines parallel to AD is equal to the side of 

 the equilateral triangle, whereas the distance between those lines 

 (ab) is equal to the height of the triangle. If d = the former 

 distance, then ds'm 60 = 0'87 X d = the other. 



It is obvious that there will be two cases according as the 



^ 

 fractional portion of -7- is a whole number or a whole number 



CL 



plus a fraction. For all practical purposes this fraction may be 

 considered as one-half. 



Suppose first that -^- is a whole number, then the number of 



A A 



planting spots in the lines will be alternately ^7- and j- +1, 



CL CL 



T> 



and the number of lines will be 7 + 1. If this last num- 



U o i X it 



^ 



ber is even, half the number of lines will contain y- planting 



d 



4 

 spots and the other half ~ + 1 spots, the total number thus 



being 



