In 1915 the Panama-Pacific International Exposition was held in San Francisco. It contained many novel and beautiful features, and was attended by vast multitudes of people. Another notable exposition was held at San Diego, beginning in 1915 and continuing in 1916. Chapter XII “The Groves Were God’s First Temples” If the people of this century continue the destruction of trees as they are doing at present, a hundred years from now this will be a world without forests, a woodless, treeless waste. What a desolate picture is this! What a grave charge will the people of the future have to bring against us that we recklessly destroy the trees, one of God’s most beautiful and useful gifts to man, without even an endeavor to replace the loss by replanting! During the last hundred years the American lumber belt has moved westward over a wide space. In the early days of our history nearly the entire supply came from Maine, and what interesting stories we have of those brave pioneer loggers and settlers! Gradually the noble woods which furnished the tall, smooth masts for which American ships were famous, were destroyed; and the ringing ax blows were then heard in the forests about the Great Lakes and in the middle Southern states. This supply is by no means exhausted, but to-day the heart of the lumber interest is on the Pacific coast. Around the great central valley which is drained by the Sacramento and the San Joaquin rivers, six hundred and forty miles long, lie mountain ranges on whose slopes are some of the noblest forests of the world. To the north of the central valley the trees of the east and west join, forming a heavily wooded belt quite across the state. In the trade, the greatest demand is for lumber of the pine and fir trees, and of these California has as many species as Europe and Asia combined. She has, indeed, only a little less than one fifth of all the lumber supply of the United States. Her most valuable tree for commerce is the sugar pine. It attains a diameter of twelve feet or more and is often two hundred feet high. But the most interesting trees of California and of the world are the Sequoias, the oldest of all living things. Very far back, in the time of which we have no written history, in the moist days of gigantic vegetation and animals, the Sequoias covered a large portion of the earth’s surface; then came the great ice overflow, and when that melted away, almost the only things living of the days of giants were the Sequoias of middle and upper California, and those on some two thousand acres over the Oregon line.