2Sg 



Let us therefore take the figures which the trees Nos. 4, 12 and 

 20 have given in the two years. 



These trees were tapped in both years in nearly similar weather 

 conditions, a factor which must be considered if we wish to make 

 just comparisons. 



The number of incisions, as was the case in both years, was not 

 precisely the same, but this small difference cancelled the drawback 

 of the unfavourable method of tapping. 



Number of Tree. 



1901. 



1902. 



4 



12 



20 



4 



12 



20 



Height of tapping 



M. 



3 30 



259 



367 



i'S 



i'S 



i'S 



Surface tapped 



M. 2 



3^5 



277 



4'5o 



1 -g 



17 



20 



Total lengths of incisions 



C. M. 



354 



301 



405 



320 



320 



320 



Total yield 



Grs. 



792 



713 



958 



810 



780 



230 



Yield per M. 2 of tapped surface 



Grs. 



217 



257 



213 



426 



459 



615 



The above figures speak for a tapping of the tree to a height of 

 1*5 metre. 



In the year 1901, the question arose whether it was not more 

 advantageous to make fewer and longer incisions than more and 

 short ones. 



The trees 13, 14, 19 and 20 of 1901 were tapped as high as 

 possible and the incisions made 20-30 cm. long. 



In the following year 1902, the trees were tapped lower and the 

 incisions made not longer than 10 c. m. 



In 1901, the incisions were reopened on the upper as well as 

 lower edge, and in 1902 only on the lower edge. 



The results of both years were as follows : — 







1 901. 







1902. 





No. of Tree. 



















13 



14 



19 



20 



13 



14 



19 



20 



No. of rainy days, M. M. 



Height of tapping, M. 



Tapped surface M a- 



Total length of incisions cm. 



Total yield, Grs. ... 



Yield per M a. of tapped surface Grs. 



10 



3.28 



4-33 

 5.88 

 968 

 224 



4 



3-66 



443 

 667 

 630 

 142 



5 



3-o 

 3-39 

 356 

 948 

 280 



8 



3.67 

 4-5 

 405 

 958 

 213 



3 



0.65 

 0.97 

 200 

 600 

 619 



3 



0.62 

 0.91 

 160 

 460 

 506 



13 

 i-S 



2.03 

 320 

 1500 

 732 



13 

 i-5 

 2.0 

 320 

 1230 

 615 



Inasmuch as the temperature variations during both tapping 

 periods were not the same (by 13 and 14, the one in 1901 was more 



