The coffee in the upper floor, as the crop advanced, gradually increased in depth until it stood at four feet all over the floor. When at this depth, with the fans making 100 revolutions per minute, the flow of air was quite sensible to the hand placed on the surface of the coffee, and was rendered apparent by the smoke from a match following the direction of the air; at the same time the rarefaction of the air within the enclosed space was so very slight as barely to be appreciable by a very delicate mountain barometer, though it had the effect of causing the door to shut with a slam; thus showing that a slight rarefaction of the air is sufficient to disturb the balance of atmospheric pressure, even when acting through a medium of coffee of considerable depth. The current of air thus established continued to flow without interruption until the fans were stopped. A cold glass tumbler taken into the store in a warm day, when the fans were not in motion, became instantly dimmed and wet by the precipitation of moisture from the internal air. When another glass was taken into the store, one minute after the fans were put in motion, it remained clear, without a trace of moisture. A very satisfactory result soon showed itself, viz. that whilst the temperature of the air as it entered the moist coffee was 80° in a warm day, the temperature of the coffee itself, as indicated by an immersed thermometer, was only 58°; the wet coffee being invariably coldest when the air that was made to pass through it was warmest. This paradox admitted of easy explanation, when it was considered that each bean of undried coffee was under similar circumstances to evaporating vessels of water placed in a draught of warm air for the purpose of cooling the water. The cold thus produced was, therefore, the necessary concomitant of the evaporation that was going on, and the difference between these temperatures afforded a measure of the drying power in different states of the weather. The circumstance of the hot air lowering the temperature of the coffee was also favourable in another point of view, seeing that it has been shown that heat is one of the conditions which promotes mouldiness, or the germination of fungi. Every bushel of parchment coffee contains half a cubic foot of air, a fact ascertained by a bushel which took thirty-three measures of water to fill it. When full of newly-washed coffee it took thirteen of these measures of the water to displace the air from the interstices of the beans without overflowing, so that we have 13--33 of air in a bushel of coffee; in other words, half a cubic foot. Hence, the fans in use are capable of giving a fresh atmosphere to 28,000 bushels of coffee every minute, or in the same time four fresh atmospheres to 7000 bushels.