67 



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 de- 

 composition 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 dif- 

 fused 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 in- 

 fluence. 



The fans at Eathoongodde 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 ma- 

 chines, 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. 



In Mr. Clerihew's modification of the blade each film of 

 air, so to speak, flows into the fan directly, until it impinges 

 on the curvilinear part of the blade, and from that point is 

 thrown at a right angle towards the periphery. The column 

 of air being thus less distorted in its progress, there is not 

 only a greater quantity discharged, but much less power is 

 consumed in effecting that discharge in the common fun it 



