493 



THE FARMER'S MAGAZINE. 



rial to be dried is placed in a chamber, into which the 

 heated air is forced, passing ofF, after permeating through 

 the mass, by a ventilation at the top of the chamber. 

 By simple means, the temperature of the air issuing from 

 the pipes over the furnace can be regulated to a 

 great nicety, from a heat capable of melting lead, 

 to that of the summer's softest gale. The drying 

 power of the apparatus will be best proved by the state- 

 ment of a fact or two gathered from the experience of 

 those who have used it for wood-drying purposes. " A 

 saw-maker, of well-known reputation in London, sent 

 to be seasoned a piece of rich beech, of which saw- 

 handles are made, and which he would vouch for having 

 been in his possession for twelve years, and during four 

 years of the twelve, it had been lying on the tie-beams 

 of a roof immediately over a smith's forge. From its 

 appearance and sound, this wood would have been pro- 

 nounced thoroughly dry ; yet, after being exposed to a 

 current of heated air at a temperature of 240 degrees, 

 for about two days, it lost 11 per cent, of its weight." 

 A violin, which had been in the possession of a party 

 for sixteen years, its age previous to its coming into his 

 possession not being known, lost on being subjected to 

 the process, in the course of eight hours, as much as 

 5| per cent, nearly of its weight. These facts we give 

 as illustrative of the drying powers of currents of heated 

 air. 



There can be no doubt that great benefits would arise 

 from some simple apparatus by which currents of 

 heated air could be quickly and economically obtained, 

 to be applied to the drying of grain, either while in con- 

 junction with the straw, or after being separated from it. 

 The chamber for heating the air would be a matter of 

 easy attainment. In nearly all improved farm-build- 

 ings, a steam-boiler or steaming apparatus is met v^ith ; 

 this wiil provide the heating-medium. A chamber or 

 steam-chest should then be provided, in which r.nd 

 t&rough which externally, from end to end, or side to 

 side, a series of pipes should be inserted. The steam, 

 being admitted to this chamber, envelopes the peripheries 

 of these pipes, raising their temperature, and that of 

 any air which may be contained in or passed through 

 their interior. Let the openings of all the pipes on one 

 side of the chamber be covered with a hood or external 

 casing, which hood should converge to a single pipe of 

 area nearly equal to the combined area of apertures of 

 pipes passing through the chamber. The same should 

 be done at the other side of the chamber. One of the 

 hood pipes will be that through which the fanners pro- 

 ject the air to pass through the pipes . the other will be 

 that which will lead the heated air as it passes from the 

 jiipes to the chamber or receptacle in which the grain 

 is placed which is to be subjected to the drying process. 

 Jn place of steam, air heated in a furnace or by contact 

 v.'ith hot surfaces may be used as the drying medium. 

 And instead of pipes, a series of flat chambers placed in 

 zig-zag fashion may be constructed above a furnace or 

 a'ongside of the steam-engine boiler furnace, and 

 through which air may be blown by a fan, and passed 

 at once into the drying chamber. Further, in addition 

 to the drying of grain detached from the straw by the 



method here detailed, it is obvious that the plan is ap- 

 plicable to the drying or keeping dry of the grain in the 

 sheaf as stored up in the ordinary stacks ; for it is only 

 the addition of a tube well perforated with holes running 

 up the centre of the stack, and through which the 

 heated air can be forced, that is required to make the 

 plan available. 



But to return to the drying of grain as detached from 

 the straw : it is clear that the method described, of 

 forcing currents of heated air through lying masses of 

 grain, will be most quickly carried out where the bulk 

 of the mass is reduced to a minimum. The economy 

 of the process will be in proportion to the rapidity with 

 which all parts of the mass, and all parts of the individual 

 grains constituting the mass, can be subjected to the 

 action of the currents of heated air. This leads us to 

 the philosophy of the process of drying grain in 

 masses. 



If we direct our attention to the simplest of practised 

 methods for drying grain by artificial heat, namely, the 

 kiln, we find that the grain placed en masse on the per- 

 forated tiles, which form the floor of the chamber, is under 

 circumstances most disadvantageous to its rapid thorough 

 and uniform drying. Placed in a thick layer on the 

 tiles, the moisture evolved from the lower strata has 

 to ascend through, and pass in contact with the 

 strata above ; the particles constituting these upper 

 strata necessarily imbibe the moisture thus coming in 

 contact with them ; and this before it can be expelled has 

 to be subjected to a temperature which may be too high 

 for the lower strata on which it rests. If, therefore, the 

 heat of the kiln is regulated so as best to dry the 

 stratum or strata immediately subjected to it, that is 

 which lie on the perforated plates, it will be too low to 

 pffect as quickly and surely as desirable the upper 

 strata which are in the receipt of the ascending moisture 

 of the lower ; or on the contrary, if the heat supplied is 

 of a temperature sufficient to dry the upper strata, it will 

 be too high for the lower. We may thus find in prac- 

 tice different strata of grain under widely difi"erent cir- 

 cumstances of drying, thus precluding all chance of 

 attainment of uniform drying. True that in practice 

 this uniformity is attempted to be attained by repeated 

 shovelling and turning over of the grain as it lies on the 

 tiles. We say attempted to be attained ; for the inherent 

 clumsiness of the process precludes all possibility of 

 perfect adjustment of the so-prepared grain to 

 the peculiar temperature which secures the right de- 

 gree of drying. From this slight investigation of the 

 circumstances under which kiln-drying is performed, we 

 may deduce as a rule or standard of correct drying the 

 following : " That every individual grain shall have each 

 portion of its surface subjected to the drying influence, 

 and the process so under control that it can be regulated 

 to give the merest shade of surface drying, up to and 

 through all the gradations ofscorching and burning." This 

 standard or rule involves two necessities of operation: 

 first, that the temperature shall be easily regulated ; and 

 second, that means shall be provided, by which each 

 grain shall have its due share of the heating medium. 

 The reader anxious to have a resume of the plans by which 



