FUTURE DEVELOPMENTS 205 



hardly any corn grown at all, but where the whole farming 

 industry turns upon the production of milk, butter, cream, 

 and calves. One may travel many miles in some of the 

 fertile valleys of the Upper Tyne, and hardly ever see any 

 arable land at all. No doubt some of the land is too far 

 removed from the rail and road, but there is still a large 

 area of land which could be used for the growth of, at any 

 rate, oats and potatoes. 



Greater care is needed in the storage of farmyard manure. 

 Much loss occurs by drainage, and it is only by persistent 

 care that this loss can be reduced (seep. 52). A greater 

 amount of artificial manures could also often be satisfactorily 

 employed. Even where artificial manures have been em- 

 ployed to a fairly large extent, it will often be found that 

 increasing quantities will still pay. It is very rare indeed 

 that the amounts of manuring in practice are sufficiently 

 large to reach the stage when the " I^aw of Diminishing 

 Returns " comes into force. There is probably hardly any 

 enterprise that has been so little exploited in this country 

 as the land, consequently it is to be expected that it will 

 yield the best returns for labour and capital. 



Economic Production of Meat in Winter. — 

 Medium cows and bullocks may be taken to breathe out 

 about 8 cubic feet of carbon dioxide in an hour, and it is 

 usually considered a good allowance to give 600 cubic feet 

 of air space and 30 square inches ventilation to each cow. 

 Assuming a velocity of air current equal to a wind of one 

 mile per hour through the opening, then the air in motion 

 at the disposal of the cow during one hour is about twice 

 the air at rest in the byre. Probably rather less than this 

 allowance is generally given, and we may assume on a 

 general basis that a cow has to heat up and moisten iioo 

 cubic feet of air. If there were no loss of heat by conduction 

 through the walls and roof, the iioo cubic feet of air passing 

 per hour through the ventilators, rising in temperature 

 from 50° F. (10° C.) to 68° F. (20° C.) and evaporating the 

 water necessary to saturate it, there would be needed 

 239 calories per hour. The. actual heat produced by the 



