THE RAISIN INDUSTRY. 49 



the San Diego districts. In Riverside and Redlands, the thermometer 

 seldom reaches one hundred and nine degrees Fahrenheit in the shade 

 during the summer, and in winter seldom goes below twenty-four 

 degrees Fahrenheit, while twenty-eight or twenty-seven degrees Fahren- 

 heit is no unusual occurrence once every year, but is considered the 

 extreme of the season. It may thus be seen that raisin vineyards and 

 orange orchards may be and actually are grown side by side in every 

 part of San Bernardino county, and this is a distinct characteristic 

 of the district, which, however, it shares with Orange and San Diego 

 counties. The warmest months are August and September, and 

 October is generally fine for drying. So is November, and only twice 

 (in 1885 and 1889) has there been any serious difficulty in drying the 

 grapes. In two other years the crop has suffered slightly, but during the 

 majority of seasons in the months of November there has not been any 

 rain on the mesa lands, and it is this absence of fall rains which makes 

 it possible for the raisin-grower to dry his crop without any other 

 appliances than raisin-trays. Dew and fogs are very rare, and occur 

 only very seldom during the summer months. When they do occur 

 at this time, they are of but short duration, and last perhaps only 

 from five to seven o'clock in the morning. In the fall of the year, in 

 October and November, the desert wind blows warm and dry, and 

 hastens the drying of the raisins. It may blow three or four 

 times during the season, but has also been known to be entirely 

 absent. The rain in the winter season is light, in Riverside twelve 

 inches being an exceptionally wet season. From six to eight inches 

 are the usual rainfall, while again the actual average for Riverside is 

 six and one-fourth inches. In Ontario the rainfall in 1887 was 8.21 

 inches, and in 1888 9.23 inches. 



Irrigation. In Riverside grapes cannot be grown without irrigation 

 on the mesa lands, with the exception of one or two localities in the 

 arroyo. In the Ontario district, raisin grapes may be grown without 

 irrigation in the center of the valley, but on the mesas, higher on the 

 sides, they must be irrigated, and even in localities where they could 

 be grown without artificial irrigation the same is always practiced 

 whenever it can be obtained. Less water is, however, needed than 

 in the San Joaquin valley, but more than would suffice in El Cajon. 

 Through the nature of the gravelly subsoil, the raisin land cannot fill 

 up with water. Seepage is only possible to a limited degree; summer 

 irrigation is always required. The vines are irrigated three times a 

 year, in April, June and August. The system of furrows is used, and 

 a ten -inch flow is considered enough to irrigate one acre of grapes 

 during one day and night each time. In Ontario the raisin grapes are 

 irrigated every five weeks, not, however, while they are in bloom, as 

 it is considered best to wait until the berries are well set. In Redlands, 

 one irrigation after the winter rain ceases is considered enough, even 

 on soil with thirty feet to water. 



Soils. The soil in San Bernardino county varies considerably. 

 In Riverside and Redlands the best soil is a reddish loam, with some 

 sand and gravel. But in Riverside we also find sandy soil of lighter 

 color and strength, which, however, is less suited to grapes. In 



