The Douglas Fir produces excellent timber, and is a most valuable forest tree, not only on that account, but because of its adaptability to varying conditions of soil and climate. It is the most widely distributed of all American forest trees, and the area of its distribution is spread over thirty-two degrees of latitude, and from end to end of this range it has, in the words of Sargent, "to endure the fierce gales and long winters of the north, and the nearly perpetual sunshine of the Mexican Cordilleras; to thrive in the rain and fog which sweep almost continuously along the Pacific coast range, and on the arid mountain slopes of the interior, where for months every year rain never falls." It appears to thrive best where the air is humid and the soil well drained. It begins to bear cones about its twenty-fifth year. The straight tapering trunk is largely used for the masts and spars of ships, its suitability for this purpose being evident to all visitors to Kew who have gazed at the flag-staff set up in the arboretum. This pole is 159 feet long, with a circumference of 6 feet at the base, tapering to 2 feet 2 inches at the top, and weighing about 3 tons. It was brought from Vancouver Island, and an examination of its rings before it was set up showed that it represented the growth of about 250 years. The full life of the Douglas Fir is estimated to be about 750 years. * * * * * [Illustration: _Pl. 164._ Stone Pine.] [Illustration: _Pl. 165._ Bole of Stone Pine.] The Stone Pine (_Pinus pinea_).