In these applications of natural and artificial heat to the curing of coffee, the heat is conveyed by the air through the whole depth of coffee in such a manner that each bean feels its influence, whilst the watery products elicited by the heat are at the same time, and by the same means, carried off. It cannot be doubted that these applications are far more effectual than any of the modes hitherto in use; in some cases stoves were employed in the apartment containing the coffee, but it is obvious that their influence could not extend beyond the surface of the mass, and that, if the apartment was closed, there was no provision for carrying off the air that had become loaded with moisture due to its temperature; whilst, if the apartment was open, so as to afford a free draught of air, the greater portion of the heat given out by the stove was carried out before the heated air could act on the coffee. In other cases, heating pipes of various kinds were used below the floors on which the coffee was placed. This arrangement, however, has the effect of injuring the coffee, by steaming it; no provision being made for carrying off the excess of hot watery vapour which accumulates within the mass, but, on the other hand, the natural processes of decomposition are assisted and promoted. The construction of Mr. Clerihew’s heating apparatus is simple, and a moderate supply of fuel has a considerable effect in raising the temperature of cold damp air before it is brought into contact with the coffee through which it is drawn by the aid of the fans. This heated air becomes diffused throughout the whole of the chamber, which extends beneath the ground-floor in such a manner that no portion of the coffee which is on that floor can be free from its influence. The fans at Rathoongodde are much more powerful than those in common use, the peculiarity in the shape of the blade giving them a great advantage as air-moving machines, in so far as the indraught is concerned, whilst one-half of the periphery being open a ready exit is afforded for the discharge of air. In the ordinary fan, if a smoking match is applied to any part of the indraught opening, the air will be seen to flow towards a neutral point in the centre of the fan, following a spiral direction, and thence in the periphery of the fan.