250 THE FOREST LANDS OF FINLAND. 



and different phenomenon occasioned in the same way. 

 It is of frequent occurrence at the Cape of Good Hope, 

 and in local phrase is spoken of as the Devil's Table-Cloth 

 on Table Mountain. 



At these times the summit of the mountain is covered 

 with a dense mass of beautiful white fleecy cloud in con- 

 stant flow over the precipice, and pouring down the almost 

 vertical front of the mountain facing Table Bay as if 

 threatening to bury in an avalanche the capital of the 

 colony at its base ; but long ere it reaches the town, not- 

 withstanding the continuous flow, it stops ; to that line it 

 flows on continuously, but beyond it not ; there the cloud 

 in unceasing flow terminates, the spectator sees not why. 



The beautiful and interesting phenomenon is occasioned 

 by a south-east wind, which, up to the Table Mountain 

 range, was undimmed. The wind was strong, but the sky 

 blue and serene, though the wind was loaded with vapour 

 vapour dissolved and invisible. 



But passing over Table Mountain the elevation of this 

 is such that the decrease of temperature, consequent on 

 expansion under diminished pressure, bringing this below 

 the dew-point, the moisture is deposited by the air in the 

 form of a cloud, which, as it reaches at a lower level to lee- 

 ward, a locality with a higher temperature, the moisture is 

 again absorbed, and the air loaded with it is again trans- 

 parent, as is all the air around, and as it was itself before 

 passing over Table Mountain in its course. 



From Claremont, or Wynberg, or the Flats, or any place 

 to the back of Table Mountain, it may be seen that the 

 cloud is not blown to the mountain, but that there it first 

 appears ; and if some few cloudlets, formed over the crests 

 of hills belonging to the range situated to windward, be 

 seen sailing towards it, it is evident that they are ' A 

 sailing, a sailing with the wind,' and not attracted only, 

 for none are seen floating toward the Table-Cloth in other 

 direction than that in which the wind blows. 



Of this phenomenon Sir John Herschel writes, ' That 

 the mere self-expansion of the ascending air is sufficient to 



