MECHANICS AND USEFUL ARTS. 119 



liour in sacks. Brother Jonathan puts his in barrels, which does not 

 thoroughly answer. * * * If Brother Jonathan wishes really to pre- 

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

 dry and cool, and hermetially seals them in tin cans. This also is a 

 common process to prevent goods from being damaged at sea. 



" There can be no doubt that if we were to put dry wheat in an her- 

 metically 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 reservoir : 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 very 

 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 water, it will clearly pay to put wheat in huge canisters 

 of iron. The wheat canister, in short, should be a wrought or cast metal 

 tank of greater or less size, according to the wants of the owner, whether 

 for the farmer's crop or the grain-merchant's stock. 



" This tank should be constructed of small parts, connected by screw- 

 bolts, and consequently easily transported from place to place. The 

 internal parts should be galvanized, to prevent rust, and the external part 

 also, if desired. It should be hermetically tight at all the points, and the 

 only opening should be what is called a man-hole that is to say, a 

 canister-top where the lid goes on, large enough to admit a man. When 

 filled with grain, the top should be put on, the fitting of the edge forming 

 an air-tight joint. Wheat put dry into such a vessel, and without any 

 vermin, would remain wheat any number of years. But an additional 

 advantage to such a reservoir would be an air-pump, by the application 

 of which, for the purpose of exhaustion, any casual vermin would be 

 killed. If the grain were moist, the same air-pump might be used to 

 draw or force a current of warm air through it, to carry off the moisture. 

 By this process, and subsequently keeping out the air, the grain might be 

 preserved for any length of time. As the reservoir would be perfectly 

 air-tight and water-tight, it might be buried in the ground with perfect 

 safety ; and thus cellars might be rendered available for granaries, econo- 

 mizing space of comparatively little value. The grain would be easily 

 poured in from the surface ; and to discharge it, an Archimedean screw 

 should be used. The size of the reservoir should be proportioned to the 

 locality, and it should hold a specified number of quarters, so as to serve 

 as a measure of quantity, and prevent the expense of meterage. * * * 

 If constructed above the ground, a stair or ladder must communicate with 

 the upper part, and the lower part must be formed like a hopper, for the 

 purpose of discharge. For many farm localities this arrangement might 

 be best, and wheat might be thrashed into grain direct from the field and 

 stored. * Granaries of this description would occupy less 



than one-third the cubic space of those of the ordinary description, and 

 their cost would be less than one-fifth. * With this security 



