THE OLIVE 



39 



growing, first consult the thermometer. A mean temperature of 

 sixty-one degrees Fahrenheit, from the first of March to the end of 

 December inclusive, will be sufficient guarantee; or this same mean, 

 from the beginning of the flowering period — say May twentieth to 

 the end of December — will ripen the berries. Where the summer 

 heat is greater the fruit will ripen earlier. 



The olive begins to move in March at a temperature of fifty-two 

 degrees, it buds at fifty-nine degrees and flowers at sixty-seven de- 

 grees. The blossoms set at a temperature of seventy-one degrees of 

 heat, and to ripen the fruit a minimum of eighteen thousand five 

 hundred degrees of heat is necessary, dating from the period in 

 March when it first began to move. A good general rule to rely 

 upon would be, that where one can obtain a mean temperature for 

 spring of fifty-six degrees; for summer, of seventy degrees; for 

 autumn, of fifty-eight degrees and in winter a minimum of twenty 

 degrees the olive can always be successfully cultivated; bearing in 

 mind, however, that some varieties require more heat than others and 

 that peculiarities in the atmosphere or the soil may make it impossible 

 to grow the olive even with this temperature. To obtain the mean 

 temperature with the necessary exactitude requires careful observa- 

 tion at least three times a day, and a minimum thermometer to show 

 the lowest temperatures during the night and early morning is im- 

 perative. A recent invention, however, has simplified this labor very 

 much; it is known as Drapers' Recording Thermometer, and con- 

 sists of a dial, driven by clock work, which makes a complete revo- 

 lution in one week and as it revolves under a pen attached to the 

 thermometer proper a curved line in red ink is drawn on the face 

 of the dial, which shows by lines thereon the exact temperature of 

 the air at every hour during the day and night. The only attention 

 this machine requires is to change the dial once a week, to wind the 

 clock at the same time,, and to feed the pen with 1 a few drops of pre- 

 pared ink. The w T eekly record dial is then filed away, and thus 



