Mab.1903.] botanical SOCIETY OF EDINBURGH 409 



Doncaster and Sheffield. The tree was felled in 1885, 

 when it contained altoorether 1000 cubic feet of market- 

 able timber. Another portion of the bole (which was 

 18 ft. long, or the same length as the one represented) had 

 been cut up and sold. Thus the bole originally was one 

 straight piece 36 ft. long without a branch, and had an 

 average diameter of about 5 ft., all sound and clean wood. 

 Certainly it was the finest timber tree we ever saw, A 

 cross section of this tree displayed admirably the annual 

 rings, from the centre to the circumference, and thus 

 afforded a splendid test of De Candolle's theory. From 

 the heart to the circumference it measured 27f in., and if 

 we compute the age of the tree according to De Caudolle 

 by allowing one-twelfth of an inch for each year's increase 

 in diameter, the tree had been growing six hundred and 

 sixty-six years, but really it was only two hundred and 

 twelve years old, according to the testimony of the annual 

 rings. The annual rings were not uncertain or confused, 

 on the contrary they were clear and legible throughout, 

 and furnished such evidence of the tree's age as would 

 have convinced De Candolle himself. 



If Prof. Burnett had seen the section whilst he was 

 engaged in calculating the age of the Cowthorpe Oak, it 

 is likely he would have taken the ratio of yearly increment 

 from the section, and rejected that of De Candolle's theory. 

 Had he done so, he would have made out the Cowthorpe 

 Oak to be, not sixteen hundred years old, but only five 

 hundred and forty-five years. We suppose his calcula- 

 tion would be something like this — at 5 ft. from the 

 ground the Cowthorpe Oak girths about 36 ft. Divide 

 this dimension by three, and roughly the diameter is 

 found to be 12 ft. Half this is 6 ft., or 72 in., which 

 would represent the radius. The radius of the section is 

 about 28 in., in which are 212 annual rings. How many 

 annual rings ought there to be in 72 in. — the radius of the 

 Cowthorpe Oak ? Answer 545. 



But we cannot accept the age of the old tree from any 

 calculation based on ratios, whether they be those of the 

 section or of De Candolle, or of any other tree. For no two 

 trees grow alike, and no one tree increases in the same 

 ratio one year after another. And if a small section were 



TB.\X.S. EOT. SOC. EDIX. VOL. XXII. ' "2 D 



