contained, had it extended itfelf upwards to the 

 length the branches are ^meafurable. r The foifi* 

 imaginary ones tliat I have adopted, therefore, may 

 be confidered as a continuation of tK^^lhaft to^e 



extent of. 112 feet. Then, ' ^ ' ^^^' -'- 



As'ihe tK^df thelfeaft Ifi Ss ^^ y?ar^a^ ^qu^ 

 td lo fe^t girt ; in its* 95)th year, by the addition 

 of one- fourth of ah inch yearly, it will girt 16 

 inches in that place ; lefiening in id advances to- 

 wards the top, which is fuppofed to have gained 

 two feet; this at 15 inches girt is cq^ial to three 

 feet one inch. 



ioIn?its II ith year, the fame part of die fhafc will 

 be 1 9 inches girt j and four feet the fuppofed length 

 of additional timber will be equal to nine feet, as 

 the mid-girt will be l8 inches only. 



In the next period, the girt at theT^e place will 

 be 22 inches. This, if continued fix feet, at 20 

 inches only in the girting-place, is equal to 1 6 feet 

 eight inches. 



To proceed : the old top of the Ihaft now takes 

 13 years to increafe to 25 inches, and its advanced 



length 



