THE OLIYE 



43 



Wherever eighteen thousand five hundred degrees can be ac- 

 cumulated before frost the olive will ripen, so that if this num- 

 ber of degrees is shown by October in any certain locality, then the 

 olive will ripen there in that month; but in others, where frost in- 

 tervenes, the olives must be left hanging on the trees for a longer 

 period. This, however, should not extend beyond the end of Feb- 

 ruary, as a later date than this is prejudicial to the welfare of the 

 trees. The lesson derived from these tables seems to be that where 

 the sum total of degrees for the year does not reach twenty-one 

 thousand degrees Fahrenheit, the olive fails to ripen ; this we see in 

 the following table, is the case in Sienna, Benevento, Perugia, 

 Bologna, Milan and Turin, and also that this is the fact where the 

 temperature falls below fifty in Xovember. Whether this will prove 

 to be as true in California as in Italy experience alone can determine, 



The following table on page 44 is presented in centigrade degrees, as 

 in Fahrenheit it would fail to indicate the object intended, which is the 

 exact period when the olive ripens. The reason of this is, that in 

 Fahrenheit thirty-two degrees of cold are always included which 

 are unnecessary and confusing in deciding the period when the 

 olive ripens, as only degrees of heat are needed. This period is 

 reckoned beginning from the first of June up to such a date as 

 shall give three thousand nine hundred and eighty-two degrees of 

 heat, which is the amount necessary to ripen the olive. As soon 

 as this number of degrees is reached, even though it be the first of 

 October, there the olive will ripen at that time. To change a daily 

 or average temperature Fahrenheit to Centigrade subtract 32° and 

 divide by 1.8, the result will be Centigrade degrees; thus <52 = 

 Fahrenheit — 02 ls 2O== " - 110 Centigrade. 



To change Centigrade to Fahrenheit multiply degrees of Centi- 

 grade by 1.8 add 32° and the result will be degrees Fahrenheit. 

 Thus 20° Centigrade 20x1 .8+32=68° Fahrenheit. 



