EXPECTATION VALUE. 127 



table at page 122. The expenses are expected to be as 

 follows : 



Cost of formation every 80 years = 60 shillings. 



Annual expenses for administration, taxes, etc. = 3 shillings. 



Interest = 2J per cent. 



The expectation value of the soil will, in that case, amount 

 to: 



2225 + 4 x l-025 30 + 36 x l'025 40 + 67 x 1-025 30 

 <? = _ + 86xl-025 20 +91 x 1-025 10 - 60 x 1-025* _ 3 

 "l ; 025* 



Calculating with the tables at page 394, the above becomes 



S e = (2225 + 4 x 3-4371 + 36 x 2-6851 + 67 x 2'0976 + 

 86 x 1-6386 + 91 x 1-2801-60 x 7'2096) x '1610-120. 



S e = (2225 + 13-7484 + 96-6636 + 140-5392 + 140-9196 

 + 116-4891 - 432-5760) x '1610 - 120. 



S e = 2300-7839 x '1610 -120 = 250 shillings = 12 10 0. 



This shows that, under the above conditions, and calculating 

 with 2J per cent, compound interest, it pays to plant Scotch 

 pine on land of the III. quality, if it can be purchased for 

 ^12 10s. an acre or under. 



Assuming now that an acre of land is planted with beech, 

 that it yields the returns given in the money yield table at 

 page 123, and that all other conditions remain the same, the 

 expectation value of the soil will be 



S e = 



3002 +jtt x 1-025 30 +91 x 1-Q25 20 +123 x 1-Q25 10 -60 x 1-Q25 80 



l-p25<w-l 

 -120. 



e = 366 shillings = 18 6 0. 



It follows that under the above conditions it pays to plant 

 beech on lands of the III. quality, if it can be purchased for 

 18 6s. an acre or under. 



Note. It must not be overlooked that a beech soil of the 

 III. or middling quality, would at least represent a soil of the 

 II. quality, if planted with Scotch pine. 



