168 tresident's address. 



base, at which part the bark alone is given at 18 inches in 

 thickness. 



Mr. D. Oliver's investigations were made on the growth, in di- 

 ameter, of the stems of Dicotyledonous {Exogenous) Angiosperms ; 

 whereas the Wellmgtoma is a Dicotyledonous Gymnosperm ; yet 

 the increase of the stems in both these sections will be found to be 

 carried on after a similar manner; and that is, by the formation 

 year after year, of concentric zones in the wood. So it would be 

 important to continue his mode of observation on the stem of 

 this new tree, and to endeavour to determine other questions 

 connected with the growth of its wood. And, indeed, we may 

 all fully expect to witness, in a few years, the growth of this 

 remarkable tree ; for, I understand, many seedlings are promising, 

 and will most likely be able to bear the changes in our variable 

 climate. Now, from a computation of the concentric zones, or 

 layers of wood, in the stem, either of an Angiospermous, or a Gym- 

 nospermous tree, the age of it may be pretty well ascertained. 

 RejDort says, from such a computation of some of the " Mammoth 

 Trees," and from a comparison of the diameters of their stems 

 with the supposed annual zones, that the largest of those existing 

 trees must have numbered full 3,000 years. 



And this is a question worthy of some little attention. The 

 account of the portion of the Mammoth Tree, which I saw last 

 spring, when privately exhibited in London, gives the diameter 

 at its base = 31 feet, and the bark at the same spot = 18 inches 

 in thickness. But, as I do not know whether that diameter in- 

 cludes the thickness of the bark, I will conclude it does, and 

 deduct twice the 18 inches = 36 inches = 3 feet, from the 31 

 feet, and call the diameter of the wood-circle = 28 feet. De 

 Candolle estimates the increase of the Yew tree, in breadth of the 

 stem, at about one line, or a 12th of an inch, in a year. On this 

 calculation, I find that the diameter would be 336 inches = 

 4,032 lines, which should signify the number of years of that 

 Mammoth Tree. Also the Editor of the "Gardener's Chronicle" 

 states, he thinks it a fact that that tree did not exceed in growth 

 two inches in diameter in twenty years, which would be 24 lines 

 in twenty years, or l-6th more than De Candolle's estimate; 

 hence, this would make the age of the tree to be 3,360 years. 



