THE OLIVE 43 



Wherever eighteen thousand five hundred degrees can be ae- 

 €umuhited 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 hani>:ino; on the trees for a lonoer 

 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 de2:rees for the vear does not reach twentv-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, ajul also that this is tlie fact where the 

 temperature falls below fifty in November. Whether this will ])rove 

 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 oliye ripens. The reason of this is, that in 

 Fahrenheit thirtv-tAVO de«:rees of cold are alwavs included which 

 are unnecessary and confusing in deciding the jieriod when tlie 

 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 deorees is reached, even thou2:h it be the fii'st of 

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

 or average temperature Fahrenheit to Centigrade subtract o2° and 

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

 Fahrenheit — ■^-'J;f°=ii.ii° Centigrade. 



To change Centigrade to Fahrenheit multi^^ly degrees of Centi- 

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

 Thus 20^ Centigrade 20xl.8t32=C)8^ Fahrenheit. 



