The most important agents used in preserv ing wood are coal tar creosote, zinc chloride and mercuric chloride. Various methods of applying the preservative include brush treat ment, dipping in an open tank, application of the solution under pressure and the combina tion of a vacuum to open the pores of the wood and pressure to force the solution into them. Preservative salts that are soluble in water are of no value in the treatment of wood that is to be exposed to the elements and for this reason the creosoting processes have made most headway. Creosoting plants are in opera tion in all parts of the United States and are the most influential factors in the practical conservation of America's timber supply thus far developed. Before the European War a large part of the supply of creosote oil came from Germany. According to data gathered by the American Wood Preservers' Associa tion, the consumption of creosote oil, domestic and foreign, and zinc chloride, 1910 to 1914, inclusive, was: Exports and Imports of Forest Products. —The export business is an important factor in the lumber trade of the United States. The growth of exports of sawed lumber from the United States is indicated by the following figures: 1870, $2,817,906; 1880, $5,086.880; 1890, $9,974,888; 1900, $17,731,696; 1910, $36,774,219; 1913, $61,975,919.
The principal export markets for American lumber are western Europe, South and Central America, Mexico and the Orient. Extensive studies of these markets have been made by the Department of Commerce to encourage the de velopment of a greater foreign business, made possible by the devastation of Europe's forest resources during the great war.
As the result of this activity of the govern ment and the enactment of the Webb bill, legitimating combinations for the development of foreign trade, a number of substantial ex port corporations were formed after the close of the European War to develop this class of business.
Aside from a small quantity of valuable hardwoods, the greater part of the lumber im ported into the United States comes from Can ada. The volume of the import business has been variously affected by changes in import tariffs and by war conditions during the years 1914-18. The following table indicates the value of wood and manufactures thereof im ported from all sources during typical years from 1900 to 1917, inclusive: Tendency of Lumber The manu facture of lumber in the United States, prac tically from the beginning of the industry, has been characterized by extreme fluctuations in prices. No other industry is more sensitive to conditions affecting general business, a fact that is accounted for, to some extent, by the im mediate associauon between lumber and the building business. When building is active the
demand for lumber is proportionately active, but building is subject to extraordinarily diver sified influences that induce violent fluctuations in volume. This fact, coupled with the inten sive competition that has long existed within the lumber industry, is responsible for frequent periods of depression, in the course of which lumber prices at the mills have actually gone below the costs of production.
In a general way the tendency of lumber prices is always upward, forced thus by eco nomic influences. The lumber manufacturer is converting into a merchantable commodity a natural raw material representing a large in vestment on which interest charges begin ac cumulating as soon as the property passes into the hands of a private owner. In addition to interest on the investment, also, taxes paid on the property from the time the government — State or Federal — granted title up to the time of actual cutting are a charge that must be included in the cost of the product. The in terest item is cumulative and the tax rate has shown steady increase in most sections of the United States. Consequently it becomes neces sary for the producer to exercise care in com puting the cost of logs entering the mill and this cost is ever increasing.
Another factor that tends toward higher prices at the mills is the necessity of logging less accessible timber. When timber was more plentiful and the manufacturer was able to se lect his supply at practically his own price, the operation could be conducted without regard to conservation and the timber which presented serious logging difficulties could be passed by. To-day, however, the less accessible timber is too valuable to be ignored and is taken, even though it cannot be delivered to the mill at the low cost possible with better located stumpage. Small logs, also, are handled at considerable higher cost in the woods and through the mill, but have become too valuable to be left in the woods as they once were.
Still another potent factor in bringing about higher prices is the change that has come in labor conditions. Before the beginning of the European War wages paid in the lumber indus try were low, as compared with wage scales in other large industries, and the hours of labor were long. In some sections 11 hours and in others 10 hours constituted a day's work. One of the effects of the war was to reduce the working day throughout the Pacific Northwest to an 8-hour basis, and another was a general increase in wages, in many cases exceeding 100 per cent, with little prospect of eventual return to former wage schedules.