THE FOOD VALUE OF VEGETABLES. 29 



The heads averaged 1 lb. 12 oz. each, and the total yield from 

 one rod was 93 lb. 



Onion. — « Sutton's Ailsa Craig ' was raised under glass and planted 

 out, while ' Sutton's Improved Reading ' was sown out of doors. 



Cost entailed for one rod of each variety : 



Ai!sa Craig. Improved Reading. 



£ s. d. s. d. 



Seed . . . .10 30 



Farm manure . 50 50 



Soot .... 6 9 



Total labour ... 17 o 80 



Rent of glass ... 6 — 



Total cost . . .£140 16 9 



Yield .... 245 lb. 210 lb. 



Time in ground . • io£ weeks. 26 weeks. 



To arrive at a means of calculating the economic value we must 

 decide upon a unit of gain and also a unit of expense, and divide 

 the former by the latter. This will give the number of units of gain 

 for one unit of expense, and we may call the result the " economic 

 value," but it must be fully understood that this term only applies 

 in a gardening sense, when the produce is not sold for profit. 



I have devised the following formula which I think will meet 

 our requirements : — 



Caloric Value X Yield in pounds per rod 

 Cost of crop in shillings x Number of weeks the ground is occupied 



= Economic Value 



In setting down the Caloric Values the nearest whole number will 

 be taken. Applying this formula to our previous results we find 

 that : 



Potato ' Windsor Castle ' gives— 



83 X 176 = 14608 = approx. 69-5 as its Economic Value. 

 10 X 21 210 



Potato 1 Gordon Castle ' gives— 



83 X 272 22576 



UX^ = ^IF = approx. 977 



Peas give — 



84 X 63 5292 n ^ 



13.8 X 21 = 289F8 = a PP rox * 18 Ec °nomic Units. 



Dried Kidney Beans : 



' Dutch Brown ' give — 



311 X 1* 4665 0 



— „ J = ^ . = approx. 28 



9 X 18 162 ^ 



* Everbearing White ' give — 



311 X 12 3732 



-c7>o8- = -762- = a PP rox - 2 3 



Carrots give — 



16 x 392 6272 



-o^r^ = 198 = approx - 3I * 6 



