102 
THE PRODUCTION OF ARTIFICIAL RAIN. 
By B. 8. Paaur, Forecast OFrricra.. 
n arid or semi-arid regions the subject of rainfall in connection with 
crop production is a most important one. The question of what is the least 
amount of rain that is necessary to produce crops has been frequently ar- 
gued, but this one fact can be relied upon: good crops on other than adobe 
soil can be raised with ten inches of rainfall, if the rainfall is properly dis- 
tributed and the temperature conditions favorable. With unfavorable tem- 
perature conditions at the time the stem of the product is full of sap, forty — 
inches of annual rainfall will not assure good crops. In California the 
autumn rains begin in October and by December Ist the soil in all parts of 
the State is in condition to plow and seed. The rains of December, January — 
sertion that it is upon the rainfall of March, April and May that the crops” 
of California depend. The largest crop ever produced in the State was in 
1880 wher in April the rainfall was the heayiest on record. The years of 
great drouth in California and consequent short crops were in 1851, 1864 
and 1877. The present season to the south of Stockton and especially eet 
of si Tehachapi mountains, is similar to the year 1877. is 
ped the necessity for itiacgegl is more apparent and more ie 
is saihaae year by year, so that the same percentage of dstieien 3 in the 
total product will not prevail that did prevail in former years of deficient 
rainfall. The crate statement shows how the rainfall this season com- 
pares with the av 
_ Average sea-'Percentage of 
ota for sea- Average see" sonal July 1 ee for — 
n to date. gona to date tod une 30. eciede todate, 
Places. 
3an Francisco....... 16.10 20.88 93.93 23 
z ed Bluff........... a eee Fee eS 13 : 
Sond Seared (| 5 i 4 : rs 
Fresn Sa sees 
n the season of 1876-77 the total rainfall at Los Angeles amounted to : 
_ §.28 inches, - San Francisco to 10.00 inches, and at Sacramento 8 96 inches. 
1 total at San Francisco amounted to 10.08 inches, at Sacra- 
mento 7.87 hashies while for the least seasonal rainfall on record in 1850-51, 
at San Francisco 7.40 inches, and at sacwstis 4.71 inches fell. In a 
period of 45 years there have been fthree seasons of drouth in California, 
and in addition several years of markedly deficient rainfall when vegetation — 
h 
