The celebrated "big trees" of California are not to be confounded with the redwood described above, but belong to a different species of the same genus. The big trees are worthy of their name, as they are by far the largest in North America. When full-grown they average about 275 feet in height, with a diameter near the ground of about 20 feet. One of the tallest as yet measured has a height of 325 feet, and the largest a diameter of 35 feet 8 inches inside the bark and 4 feet above the ground. The age of one of these giants, as shown by the number of rings of growth in its trunk, is about thirteen hundred years; another, 24 feet in diameter, is twenty-two hundred years old; and a third showed over four thousand rings of growth, and must have been in its prime at the time of the birth of Christ. The trees occur in detached groves on the western slope of the Sierra Nevada in south-central California, but become more common southward, where they form a genuine forest belt. Their range from north to south is about 260 miles, and their elevation above the sea from 6,000 to 8,000 feet. "So exquisitely harmonious," says John Muir, in his charming book The Mountains of California, "and finely balanced are even the very mightiest of these monarchs of the woods in all their proportions and circumstances, that there is never anything overgrown or monstrous about them. On coming in sight of them for the first time, you are likely to say, 'Oh, see what beautiful, noble-looking trees are towering there among the firs and pines!' their grandeur being in the meantime in great part invisible, but to the living eye it will be manifest sooner or later, stealing slowly on the senses like the grandeur of Niagara or the lofty Yosemite domes. Their great size is hidden from the inexperienced observer as long as they are seen at a distance in one harmonious view. When, however, you approach them and walk around them, you begin to wonder at their colossal size and seek a measuring-rod. These giants bulge considerably at the base, but not more than is required for beauty and safety; and the only reason that this bulging seems in some cases excessive is that only a comparatively small section of the shaft is seen at once in near views. One that I measured in the King's River forest was 25 feet in diameter at the ground and 10 feet in diameter 200 feet above the ground, showing that the taper of the trunk as a whole is charmingly fine. And when you stand back far enough to see the massive columns from the swelling instep to the lofty summit dissolving in a dome of verdure, you rejoice in the unrivalled display of combined grandeur and beauty. About 100 feet or more of the trunk is usually branchless, but its massive simplicity is relieved by the bark furrows, which, instead of making an irregular network, run evenly parallel, like the fluting of an architectural column, and to some extent by tufts of slender sprays that wave lightly in the winds and