A striking illustration of the new problems and extraordinary ramifications incident to this great new industry which so suddenly came into existence in the United States is the fact that it was found necessary to despatch an agricultural expert post-haste to India to purchase enormous quantities of castor-beans, as it was at first believed that castor-oil was the only satisfactory lubricant for these new types of high-speed, high-power engines. India’s stock of castor-beans being quickly exhausted by the immensity of our demands, more than 100,000 acres of the bean were planted in the United States. Meanwhile, research work with mineral oils was carried on intensively, a lubricant eventually being developed which proved satisfactory in practically every airplane engine except the rotary type, for which castor-oil is still preferred. But the aircraft problem was by no means solved with the development and production of the Liberty engine. Far from it. To build airplanes requires wood; the best timber in the world is none too good; and of suitable timber there was a comparatively limited supply. The best wood known for airplane construction is the Sitka spruce, which combines the required qualities of strength, resiliency, and lightness. This spruce grows mostly in the Pacific Northwest, along the tide-lands of Washington and Oregon, at a low elevation. But not all the planes were built of spruce, fir, as it grows in the Northwest, being largely used for the heavier wing-beams. Port Orford cedar was eagerly utilized whenever it could be obtained. It is of somewhat smaller growth than spruce or fir, but a straighter-grained wood, harder and more dense than either of the others. Of this splendid wood there is, however, only a comparatively small quantity, 2,000,000,000 feet, perhaps, anywhere in the world, mostly near Coos Bay, on the coast of Oregon. Being less affected by water than any of the other woods, it was reserved for use in seaplanes. The government commandeered the entire supply of Port Orford cedar for aircraft production, but released it upon the signing of the armistice.