168 CULTURE OF FARM CROPS. 



made subservient to the plan of drying wheat by passing 

 currents of air through it, there can be no doubt. 



29. Grain Tanks. The usual mode of keeping grain is, 

 as our readers know, on the floors of granaries. This mode 

 is open to very grave objections, which are obvious enough 

 on consideration; to obviate these Mr. Bridges Adams has 

 proposed to use underground tanks of wrought-iron, Of 

 of these we give here Mr. Adams' own description : 



" There does not seem to be any difficulty in the matter, 

 if we can divest ourselves of preconceived ideas of the no- 

 tion that a granary or grain receptacle must necessarily be 

 a building with a floor or windows more or less multiplied 

 in altitude. We may reason by analogy as to what is the 

 cheapest and most effective means of securing perishable 

 commodities from the action of the atmosphere and vermin. 

 In England we put our flour in sacks. Brother Jonathan 

 puts his in barrels, which does not thoroughly answer. 

 If Brother Jonathan wishes really to preserve 

 his flour or his ' crackers ' undamaged, he makes them 

 thoroughly dry and cool, and hermetically seals them in 

 tin cans. This also is a common process to prevent goods 

 being damaged at sea. The Chinese, not having much 

 facility for metal manufacture, line wooden chests with thin 

 sheet-lead or tin, and pack their teas in them. In Eng- 

 land we keep our tea and sugar in cases of tinned sheet- 

 iron. We preserve meat in tinned cases, hermetically sealed. 

 We put fruit into sealed bottles. In all these cases the 

 object is to exclude the air as well as vermin. . . 

 There can be no doubt that if we were to put dry wheat 

 in a hermetically sealed tinned case, it might be kept as 

 long as the famed ' mummy wheat ' of Egypt. This will 

 readily be admitted, but the expense would be queried. 

 Let us examine into this. A canister is a metallic reser- 

 voir ; so is a gasometer ; so is an iron water-tank in a ship, 

 at a railway station, or elsewhere; and a cubic foot of 

 water-tank on a large scale will be found to cost very much 

 less than a cubic foot of canister on a small scale. And 

 if a bushel of wheat be more valuable than a bushel of 



