141 
BY THE USE OF KITES OFF THE WEST COAST OF SCOTLAND, 1902. 
entered the clouds was invariably higher than the level at which* the clouds lay upon 
the mountains. The Paps of Jura, some 2500 feet (760 metres) high, were often 
covered with clouds at times when the kites did not reach the cloud level under 
4000 feet (1220 metres), and the same rule held for lower altitudes. If, then, tlie 
lower cloud surface over a limited district he considered as approximately coinciding 
with an isothermal surface, and this does not seem improbable, it follows that 
mountain temperatures are lower than those of the free air; at least this was the case 
at Crinan last summer, for the clouds were undoubtedly lower when in contact with 
the mountains than they were when formed over the surface of the neighbouring sea. 
Thus the existence of such cloud layers on the mountain slopes at a level 
considerably lower than the clouds over the adjacent sea may be taken as an 
indication of the effect suggested, although it must be allowed that it might also be 
attributed to evaporation from the lower mountain surface. 
Further and more minute investigation alone can really decide what the explanation 
of the difference is. 
2 7 OCT 190b 
