AMERICAN FOREST TREES 177 



mound about the base of the tree, where they have been so accumulating 

 for centuries. It is fortunate that those old trees have bark from one to 

 two feet thick. They can afford to be scratched for a month or two each 

 year. 



These are the heaviest trees in America, notwithstanding their 

 wood is light. It weighs less than northern white cedar. The largest 

 bigtree trunks weigh more than 2,000,000 pounds. In order to stand at 

 all, they must stand plumb. It is a provision of nature that the old 

 trees are almost branchless, otherwise the wind would force them out of 

 plumb and they would go down. It has been claimed that the over- 

 throw of one of these giants is always brought about by one of two 

 causes. The development of larger limbs on one side than on another 

 unbalances them; or the wash of gullies undermines the roots on one 

 side, and draws the tree that way. It is currently believed that no big- 

 tree ever dies from natural causes. 



A good deal of pure fiction has been published regarding the size 

 and age of the largest of these trees. They are old enough and large 

 enough without drawing upon the imagination. The tree's base is 

 greatly enlarged, but tapers rapidly the first few feet. There is little 

 doubt that some of the trunks are over forty feet in diameter, one foot 

 above ground, but that is not a fair measurement. The point 

 should be five or six feet at least. Measured thus, about twenty-five 

 feet inside the bark would represent the largest. With the bark added, 

 the diameter would be nearly thirty feet. Probably not one tree in 

 fifty, taking them as they occur in the whole range and counting 

 veterans only, is fifteen feet in diameter five feet from the ground. 



There is also some extravagant guessing as to height. Too many 

 tourists measure with the unaided eye, or accept a guidebook's figures. 

 An authentic height of 365 feet the measurement of a fallen trunk is 

 probably the greatest. Very few reach three hundred feet. Many 

 unreliable figures have been published concerning the age of bigtrees. 

 One thing can be accepted without question; size is no proof of age, in 

 comparing one tree with another; neither is the number of annual rings 

 in a block cut from the side of a tree a reliable factor to determine age. 

 The only sure way to determine the age of one of these trees is by count- 

 ing all the rings from the pith to bark. Care should be taken not to 

 count the same ring twice, as may be done when the wood is curly. 

 John Muir counted 4,000 rings in a bigtree stump. It is believed that 

 no higher age is backed by the evidence of yearly rings. It was twenty- 

 four feet in diameter. The count of another of like size made it 2,200 

 years old; and of still another of the same size placed its age at 1,300 

 years. The Forest Service has made accurate measurement and record 



