CLIMATE 13 
surface, they must also become drier. We perceive this 
well enough in the case of our own east winds. 
5. Ocean-Currents.—These have a marked influence 
on climate. The Gulf Stream spreads as a drift over the 
surface of the North Atlantic Ocean, moving in a north- 
_easterly direction towards the shores of Western Europe, 
to which it brings the stores of heat and moisture which 
it has drawn from tropical seas. The climatic effect 
of the Gulf Stream is, however, mainly attributable to 
the winds that accompany it in its long journey from the 
Tropics. Owing to the presence of these winds, the 
fiords of Norway are free from ice all the winter, even up 
to the Arctic Circle, while on the other side of the Scan- 
dinavian Mountains, the Baltic Sea, exposed to the dry 
cold winds of Northern Russia, is frozen over for several 
months in the year. 
6. Presence of Clouds and Fogs.—Where these con- 
stitute a characteristic feature of the climate, the weather 
is raw and cold. Clouds and fogs form an effective 
barrier to the sun’s rays, and the soil, thus screened, loses 
much of the warmth that otherwise would reach it. 
Scotland is, for the most part, such a country. Holland, 
too, is cold and foggy. In Tierra del Fuego, in certain 
oceanic islands like the Falklands, and in the lonely 
island of Kerguelen in the Indian Ocean, the sun is 
rarely visible through the clouds. 
7. The Destruction of Forests.—Even in nature, 
forests may occasionally be destroyed by fire, but in 
most cases their disappearance is due to their deliberate 
removal by man. As a result, the rainfall in these 
localities has diminished, the fertility of the land has 
been impaired, and, in some cases, the whole aspect of 
the vegetation has been altered. On the other hand, 
afforestation tends to increase the rainfall, and restore 
fertility to the whole district. Thus, between 1863 and 
1878, trees were planted on 19,500 acres of barren land 
on the stony slopes of Ventoux, in Provence, France. 
These forests now yield £2,800 a year, a sum which is 
expected to increase to £3,600 in five years’ time. But 
far more important than this is the accompanying state- 
ment that “springs have reappeared, the lower lands 
have increased in value, and the village proprietors 
have found themselves suddenly enriched.” 
