OF ARTS AND SCIENCES. 95 



founded. The data wanting are the average thickness of the layers 

 towards the centre, giving the rate of the tree's growth as a young 

 and middle-aged tree, when it must undoubtedly, like other trees, have 

 increased more rapidly than in later years. 



" Dr. Lindley, I find, (in the Gardener's Chronicle,) has accredited 

 the estimate which assigns to this tree an age of above 3,000 years ; 

 stating that ' it may very well be true, if it does not grow above two 

 inches in diameter in twenty years, which I believe to be the fact.' 

 That rate would indeed give 3,500 layers at the height of five feet 

 from the ground, where it is 29 feet 2 inches in diameter. But this 

 measurement appears to include the bark, — to allow for which Dr. 

 Lindley would perhaps give up the odd 500 years. There is a fur- 

 ther consideration. At twenty-five feet from the ground the diameter 

 of the wood is nearly 10 feet 4 inches. Here the rate of two inches 

 in diameter in twenty years would give the trunk an age of only 1,230 

 years, so that, on these data, the tree in its youth would have been 

 1,770 years in adding twenty feet to its stature ! Evidently the base 

 of the trunk is enlarged somewhat in the manner of Taxodium and 

 other allied trees, when old. 



" The section of the trunk at Philadelphia has been hollowed out, 

 by fire and other means, to a shell of 3 or 4| inches in thickness. 

 Of this I have, through the kindness of the proprietor and of Mr. 

 James, a piece of the wood, including nearly three inches of this 

 section. What is now wanted, and what unfortunately I do not pos- 

 sess, is a foot or two of the wood from the central parts of the tree, — 

 a desideratum which may doubtless be supplied hereafter. The data 

 at hand, however, will suffice for determining an age which the tree 

 cannot exceed, unless it be supposed to have grown more slowly 

 during the earlier nine tenths of its existence than during its later 

 years, — which is directly contrary to the ascertained fact in respect 

 to trees in general. Now the piece of wood in my hands exhibits an 

 average of 48 layers in an inch. The semidiameter of the trunk at 

 the place where it was taken is 5 feet 2 inches. If the tree increased 

 in diameter at the same rate throughout, there would have been 2,976 

 annual layers ; which, allowing 24 years for the tree to have attained 

 the height of 25 feet, would give it an age of 3,000 years from the 

 seed. This corresponds so closely with Dr. Lindley's estimate, that 

 we may suppose him to have employed equivalent data in a similar 

 manner. How great a deduction must we make from this estimate, 



