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 counting 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 of every ring of growth in a tree that was over twenty-four feet in diameter, and it is shown that during certain periods of years the tree grew three or four times as rapidly as during other periods. The wood of bigtree is very light, soft, moderately strong, brittle, summerwood thin and dark rendering the rings of annual growth easily seen; the medullary rays are thin, numerous, and very obscure. The wood is light to dark red, the thin sapwood nearly white; it works easily, splits readily, and polishes well. It is very durable in contact with the soil. Trunks lie in the woods long periods before decay seriously attacks them; but forest fires hollow them, and finally burn them up. Enormous depressions are found in the forest where logs once lay, but which disappeared long ago, judging by the size of trees which have since grown in the depressions. The interior of some large trunks which have been worked up on sawmills showed the scars of forest fires centuries ago. The annual rings which covered one such scar showed that the burning took place 1,700 years ago. Not much can be said for the commercial uses of bigtree. Many a species of insignificant size is much more useful. Considerable quantities have been cut by sawmills. The waste is great, heavy trunks crushing badly in fall. Logs are so large that many of them are split with gunpowder to facilitate handling them. Some of the wood has been exported for lead pencils; other has been used for fence posts, shingles, and grapevine stakes, while the soft bark has been worked into novelties.