REPORT ON OREGON TERRITORY 279 extensive mud and sand flats. A survey was made of it, to which I refer for particulars. This, however, is not the case with the harbors found within the Strait of Juan de Fuca, of which there are many, and no part of the word affords finer inland sounds or a greater number of harbors than can be found here capable of receiving the largest class of ships, and without a danger to them that is not visible. From the rise and fall of the tide (18 feet all) facili- ties are afforded for the erection of work for a great maritime nation. For further information our extensive surveys of these waters are referred to. CLIMATE. That of the western section is mild throughout the year, neither experiencing the cold of winter nor the heat of summer. By my observations the mean temperature was found to be 54 F. The prevailing winds in the summer are from northwest, and in the winter from southwest and southeast, which are tem- pestuous. The winter is supposed to last from December to February ; the rains usually begin to fall in November and last until March, but they are not heavy though frequent. Snow some- times falls, but it seldom lays over three days. The frosts are early, occurring in the latter part of August ; this, however, is to be accounted for by the proximity of the mountains. A mountain or easterly wind invariably causes a great fall in the temperature. These winds are not frequent. During the summer of our operations I find but three days noted of easerly winds having occurred. The nights are cold and affect the vegetation so far that corn will not ripen. Fruit trees blossom early in April at Nisqually and Van- couver, and at the former on the 12th of May peas were a foot high and strawberries were in full bloom, and salad had al- ready gone to seed 3 feet high.