18 UNEMPLOYMENT IN THE UNITED STATES (b) For the preservation and maintenance of existing river and harbor works, and for the prosecution of such projects heretofore or hereafter authorized as may be most desirable in the interest of commerce and navigation: (ec) For prosecuting flood-control projects heretofore or hereafter authorized; and (d) For carrying into effect the provisions of the public buildings act, approved May 25, 1926, as now or hereafter amended and supplemented, in respect of public buildings within and without the District of Columbia. PUBLICATION OF INDEX OF EMPLOYMENT Sec. 7. The Secretary of Labor shall prepare and publish monthly an Index of Employment, which shall indicate the condition of employment in the United States and in each substantial portion thereof. PREPARATION OF INDEX OF EMPLOYMENT Sec. 8. For the preparation of the Index of Employment there shall be made available to the Secretary of Labor, upon his request, statistics collected or com- piled by any executive department, independent commission, board, bureau, office, agency, or other establishment of the Government. The Secretary of Labor is further authorized to utilize, to such extent as he deems advisable, statistics collected or compiled by any State or political subdivision thereof, or by any private, industrial, commercial, banking, labor, or other association or enterprise, and to obtain such additional facts and statistics as he deems necessary for such purposes. ACCELERATION OF EMERGENCY CONSTRUCTION Sec. 9. For the purpose of preventing unemployment during periods of busie ness depression and of permitting the Government to avail itself of opportunity for speedy, efficient, and economical construction during such periods the Presi- dent is requested to direct the Secretary of War, the Secretary of the Treasury, and the Secretary of Agriculture to accelerate during such periods, to such extent as is deemed practicable, the prosecution of all public works within their control. ADVANCE PLANNING Sec. 10. It is hereby declared to be the policy of Congress to arrange the construction of public works, so far as practicable, in such manner as will assist in the stabilization of industry and employment through the proper timing of such construction, and that to further this object there shall be advance planning of public works to be accomplished (a) in the case of river and harbor and flood- control works and projects and publie-building projects by means (1) of prelima- nary reports, made under the subsequent provisions of this act or existing law, as to the desirability of the project; (2) of annual authorizations of projects, the total estimates for which are sufficiently in excess of the annual appropriations made for the work thereon to result in uncompleted projects being available for the expenditure of public works emergency appropriations when made; and (3) of advance preparation of detailed construction plans and (b) in the case of public- roads projects by means (1) of advance approval of projects in accordance with the provisions of the Federal highway act, and amendments and supplements thereof, and of this act, and (2) advance preparation of detailed construction plans. PUBLIC-ROADS PROJECTS Sec. 11. (a) In addition to the projects authorized to be approved under the Federal highway act, and amendments and supplements thereof, the Secretary of Agriculture is authorized to approve emergency Federal-aid road projects for the construction, reconstruction, and maintenance of Federal-aid highways, the share of the United States in the cost of which is to be paid primarily out of public works emergency appropriations made for the purpose. Such emergency projects may be approved in advance of any such appropriation but only to such extent as the Secretary of Agriculture deems advisable in order that uncompleted projects for the expenditure of money so appropriated may be immediately available at the time such appropriation is made. If the amount apportioned to the State of the public works emergency appropriation made for the purpose is insufficient to meet the share of the United States in the cost of all approved emergency projects within the State, the balance of the share of the United States shall be