RECENT GEOGRAPHICAL EXPLORATION. 173 



sively rainy to an unusually vigorous movement of the Gulf Stream, 

 in consequence of an exceptional pressure of the southeast trade- winds, 

 which he claims produced an extensive diffusion of Gulf vapor in a 

 northerly direction, greatly mitigating the winds in the United States. 

 Others attribute these effects to a change in the condition of the sun, 

 which during the last year is said to have been in a state of repose that 

 is very rare, there being no spots or eruptions visible upon its surface. 

 The latter theorists maintain that, when the sun-spots are at the great- 

 est height, or at their maximum, the earth receives the greatest quan- 

 tity of heat ; and that, when the spots are at the lowest, or their mini- 

 mum, the heat is proportionately lessened. Others, however, dispute 

 this altogether, declaring that the observations that have been made 

 of the maximum periods of the spots on the sun's surface do not coin- 

 cide, over any length of time, with the warm and cold years, and do 

 not, therefore, justify any such inference. Monsieur de Perville, on 

 the other hand, maintains, as the result of long observations of dry 

 and rainy seasons in Europe, that they correspond with known changes 

 of the moon. In connection with which I may mention, as a curious 

 fact, derived from recent Assyrian researches, that the Babylonians 

 and Chaldeans attributed changes in the weather to the influence of 

 the moon, and kept up a system of regular observations of the moon 

 for practical purposes. 



The extreme dryness and consequent want of moisture for the fer- 

 tilization of the fields in parts of India and China, hitherto fruitful 

 and thickly populated, is attributed to the wanton destruction of the 

 forests on the hillsides. In 1879 Mr. Hilliard visited the famine- 

 stricken province of Shang-Si, in China, and found in these famine 

 districts that the trees had been extensively destroyed, and attributes 

 the want of moisture and the consequent infertility of the soil to this 

 cause. Observations made in France by M. Mathieu and by M. 

 Fautral over a period of four years, by different methods, as to the 

 effect under trees and the effect in treeless plains, led to the same gen- 

 eral results, which are as follows : That it rains more abundantly over 

 forests than over open ground, especially when the trees are in leaf ; 

 that the air above the forest is more saturated with moisture than over 

 the open ground ; that the leaves of trees intercept one third, and, in 

 some trees, half of the rainfall, and that the leaves and branches re- 

 strain the evaporation of the water which reaches the ground, moisten- 

 ing the earth four times as much as it is moistened by the rain that 

 falls upon open plains. 



Geographical inquiries are not limited to the discovery of unknown 

 countries or places, but embrace the discovery of the remains of lost 

 civilizations or cities, one of which has been discovered during the last 

 two years. The readers of the Bible will remember the frequent men- 

 tion that is made of the Hittites, a people occupying Canaan, who are 

 described in the Biblical narrative as being commercial and military, 



