G Pv A ar, the quantity is increased to the tli' 2 or 3 feel j ii -. turn* it once i:i the course of month, and Ai th i or three years, it is j >nce in two months, and - evei quart* r ; but, in proportion to the length of time it is k ptj the taming, &c. should be more lreqn ntly repeated, in eq cnce of which the grain will be much improved. In storing corn, it is requisite to leave an of a yard in width on every side of each heap, into which the com should be . as appears necessary. In the Kentish granaries, two square hol( l e at each end of the floor, and a circular one in the middle of the building, through which the corn is shifted Iron i the upper rooms into those below, ant! again from the lower rooms into the upper ones, in order that it may be the more effectually turned and aired. The .screens or frames employed for sifting the corn, are made with two partitions, for the purpose of separating the pure grain from the dUst, which falls into a bag. By these precau- tions, corn has often been pre- served sound and pure for thirty years j and it js a circumstance worthy of notice that, though by long keeping the grain deceases in bulk, yet it will yteld proportion- abty more flour, and the brad will likewise be whiter and more whole- some} as the superfluous moisture only evaporates during die frequent airing. M. Du Hamel, and Dr. Hales, have recommended various con- trivances for ventilating, or intro- ducing fresh air through corn de- posited in granaries, with a view to preserve it sweet and dry, as G R A [393 well as to secure it from wo v'il4 'T in.-ecls. This ob]ei t is to be eife&ed, by constructing grana- ries with lattice-work) and hair- cloth at the bottom. The venti- lators for supplying fresh air may be affixed to die v. all, either within or on the outside of the granary, nil the floor, or in the ceiling-, but, in the former case, it will be necessary to place the handle of thr ; lever externally, as otherwise the person working the machinery would be exposed to suffocation, when the corn is fumigated with sulphur for the expulsion of wee- vils. Small movable ventilators may be constructed on this plan, for ventilating corn in large bins deposited in granaries. Similar contrivances may be applied to the low r est floors of small magazines, so as to be worked by men stand- ing on the ground, either within or without the buildings. In the 8th vol. or the " Letters and Papers of the Bath and IVest of England Society," )kc. Thomas South. Esq. gives a description of a cheap and efficacious ventilator, for preserving corn on ship-board. This machine consists of a forcing purrtp, with perforated tubes an- nexed to i; and by means of which fresh air may be communicated to every part of the cargo. — Mr. South's air-vessel is, for the sake of cheapness, confined to a diame- ter of 10 inches; but he observes that, if the latter be enlarged to 14 inches, the effect of the ma- chine will be nearly doubled j- and if the length of the trough (by the suclion - valve) be extended 10 inches, a power will be obtained capable of ventilating a cargo of 400 to:s in the course of one hour. The price of a ventilator on the smaller plan,, is computed by Mr. South,
