paratus furnished with hose and smooth-bore nozzles of about onesixteenth inch in diameter, when discharging, under 40 pounds pressure, from each of several such nozzles, would spray about half a gallon of insecticide mixture per nozzle per minute.

A strong steam pump to be used in connection with a small oilburning boiler, the whole apparatus on a smaller scale than that described above, has been estimated at $275 by a prominent New York firm, delivered on board the cars.

There is no reason why an old steam fire engine could not be In one or readily arranged for this shade-tree spraying work. two instances a steam fire engine has been used for this purpose without modification, the object being simply to knock the insects from the trees by means of a strong stream of water. By such means as this Col. John M. Wilson, U. S. A., now Superintendent of Public Buildings and Grounds in Washington, kept the elms green at West Point several years ago, when he was superintend ent of the Military Academy. In every large city where the fire department is necessarily kept in the best condition, an engine is occasionally retired. The transfer of such a retired engine to the street department could no doubt be readily made, and a little work by a competent steam fitter would transform it into a most admirable insecticide machine. In this way the initial expenditure for machinery would be avoided.

WHEN THE WORK SHOULD BE DONE.

When the spraying apparatus has been once provided, the funds necessary for the purchase of insecticides and the necessary labor must be available at the proper time. If the work is not done promptly and at just the right time, more or less damage will re- · sult, and a greater expenditure will be necessary. During the latter part of May and the first of June, in the case of nearly all prominent leaf-eating shade-tree insects, one or two thorough sprayings must be made. In fact a second spraying, begun immediately after the completion of the first one, will be in ordinary cases as much as need be expected. In addition to this spraying work, a force of men must be employed for a time in July to destroy the elm leaf-beetle larvæ as they are descending to the ground and to burn the webs of the first generation of the fall webworm. This will finish the summer work. The winter work will consist of the destruction of the eggs of the white-marked tussock moth, the cocoons of the fall webworm, and the bags of the bagworm. The number of men to be employed, and the time occupied, will depend

upon the exigencies of the case. Upon the thoroughness of this work will depend, to a large extent, the necessity for a greater or less amount of the summer work just described.

We have now to consider what can be done by citizens where city governments will not interest themselves in the matter. It is unreasonable to expect that a private individual will invest in a spraying apparatus and spray the large shade trees in front of his grounds, therefore in spraying operations where large trees exist in numbers there must be combination of resources. This affords an opportunity for the newly invented business of spraying at so much per tree. In Bridgeport, Conn., Mr. W. S. Bullard, who was formerly and is yet for the greater part of the year a roofer and paver, has constructed several cart sprayers, and during the months of June and July (at a time, by the way, when the men in his employ are apt to be out of work) he sprays trees on the grounds. of private individuals and along the street in front of their grounds, under contract, at so much per tree, guaranteeing to keep the trees in fair condition during the season. His work has been directed solely against the elm leaf-beetle, since that is the only insect of great importance in Bridgeport. In the month of July last the writer, in driving through the streets of Bridgeport, found it easy to pick out the trees which had been placed in Mr. Bullard's care. Such elms were green, while all others were brown and nearly leafless. The defect of this plan as a general practice lies in the fact that not all property owners or residents can afford to employ a tree sprayer, while others are unwilling, since they deem it the business of the city authorities or do not appreciate the value of tree shade.

CO-OPERATIVE EFFORT.

Any effort, therefore, looking toward the arousing of popular sentiment or the banding together of the citizens in the interest of good shade is desirable. A most excellent plan was urged by one of the Washington newspapers the past summer. It advocated a tree protection league and each issue of the paper through the summer months contained a coupon which recited briefly the desirability of protecting shade trees against the ravages of insects, and enrolled the signer as a member of the league pledging him to do his best to destroy the injurious insects upon the city shade trees immediately adjoining his residence. This was only one of several ways which might be devised to arouse general interest. The average city householder seldom has more than half a dozen street

shade trees in front of his grounds, and it would be a matter of comparatively little expense and trouble for any family to keep these trees in fair condition. It needs only a little intelligent work at the proper time. It means the burning of the webs of the fall webworm in May and June; it means the destruction of the larvæ of the elm leaf-beetle about the bases of the elm trees in late June and July; it means the picking off and destruction of the eggs of the tussock moth and the bags of the bagworm in winter, and equally simple operations for other insects, should they become especially injurious. What a man will do for the shade and ornamental trees in his own garden he should be willing to do for the shade trees 10 feet in front of his fence.

Approved: CHAS. W. DABNEY, JR.,

L. O. HOWARD,
Entomologist.

Assistant Secretary.

Washington, D. C., March 6, 1896.

Forest Service Circular 97.

GIFFORD PINCHOT, FORESTER.

The Timber Supply of the United States

BY R. S. KELLOGG,

Forest Inspector.

FOREST PRODUCTS.

The lavish manner in which the United States has consumed the products of its forests and the rapidity with which our timber supply is melting away are wholly unappreciated by those who have never given the matter more than passing consideration. Familiar as all are with the use of wood for every purpose and in every industry, it is only when the various items are added that there begins to come a realization of the indispensable place the forests fill in the national economy. A conservative statement of the present yearly output of the forests is shown below, the values given being those at the point of production :

TABLE 1.—Annual output of forest products.

The total quantity of wood cut to obtain the products listed in the table was not less than 20 billion cubic feet.

Rapidly as the population of the United States has increased, the lumber consumption has increased still more rapidly. In round numbers, and allowing for incomplete reports, the lumber cut in 1880 was 18 billion feet; in 1890, 24 billion feet, and in 1900, 35 billion feet. The increase in population from 1880 to 1900 was 52 per cent., but in lumber cut 94 per cent. The United States is now using annually 400 board feet of lumber per capita, while the average for Europe is but 60 feet per capita.

Table 2 affords a better understanding of the vast amount of

lumber used.

This gives the lumber cut of the principal States since 1880. The figures for 1880, 1890, 1900, and 1905 are those compiled by the census; the total cut is estimated by assuming an average cut between census dates. This brings the total cut since 1880 to more than 700 billion feet-a truly astonishing figure when we stop to consider it. This quantity of lumber would make a floor 1 inch thick over Vermont, Massachusetts, Connecticut, Rhode Island, and Delaware, or an area of 25,000 square miles.

TABLE 2.-Lumber cut of the United States, 1880-1906.

There are some striking things shown in this table. Since 1880 Michigan has produced over 93 billion feet of lumber, or 13.2 per cent. of the output of the entire United States; Wisconsin, 70 billion feet, or 10 per cent. of the total; Pennsylvania, 53 billion, or 7.6 per cent., and Minnesota, 38 billion, or 5.4 per cent. The combined output of these four States since 1880 is almost 256 billion feet, or 36 per cent. of the total production of the United States.