22 AGRICULTURAL EXPLORATIONS IN ALGERIA. 



below the Alg-eriaii coast towns in yearly mean temperature. The 

 mean temperatures for the suumier months also are decidedly lower 

 at the California localities. The mean temperatures in winter cor- 

 respond more closely. 



Orleansville shows a remarkable resem})lance in distribution of tem- 

 peratures to the similarly situated town of Fresno, in California, and 

 in this repect somewhat less to Sacramento. In yearly mean tempera- 

 ture, however, Orleansville is nearer Sacramento. Setif, as would be 

 expected, differs considerably from Orleansville, Fresno, and Sacra- 

 mento in yearly and monthly means of temperature. Its resemblance 

 to the high plateau is expressed in the fact that the nights are always 

 cool in summer and the winter temperatures are low, falling at times 

 to 12° F. The mountain stations. Fort National and Colfax, show a 

 close approximation in monthly and yearly mean temperatures. 



HUMIDITY. 



The relative atmospheric humidity in the littoral zone is fairly 

 uniform throughout the year. Owing to the proximity of the sea it 

 is at all seasons considerable, the average for the year being 73 per 

 cent. This condition of humidity is interrupted only when, generally 

 in late summer and in early autumn, the sirocco blows for a day or 

 more at a time. The humidity is far greater in the eastern than in 

 the western part of the colony. The large percentage of moisture in 

 the atmosphere causes the discomfort from cold in winter, and from 

 heat in summer, to be out of all proportion to the actual temperature. 



The dry season, so far as the littoral zone is concerned,. owes its 

 character to the lack of actual precipitation rather than to the absence 

 of humiditv in the air. Night fogs are frequent when east or northeast 

 winds are blowing, and in August it is often t) o'clock in the morning 

 before they disappear. Dew is also copious at this season. 



Atmospheric humidity, like precipitation, decreases as one goes far- 

 ther from the coast. It is already perceptil)ly less in the mountainsj 

 and in the great valleys of the coast region than along the seaboard. 



PRECIPITATION. 



In Algeria precipitation is almost synonymous with rainfall, except f 

 in the higher mountains, for elsewhere the amount of precipitation in 

 the form of snow is unimportant. Hailstorms are fairly frequent, 

 occurring, on an average, seven times a year. Market gardens of the 

 littoral zone sometimes suffer severely from spring hailstorms, and, in 

 exceptional localities, vineyards and orchards are occasionally dam- 

 aged. Hail is more important for this reason than as contributing 

 much to the total precipitation. 



In the coast region of Algeria, as in many warm tempci-ate and 

 tropical countries, the distribution of the rainfall is more important 



