Nearly 1,200 beams of concrete or reinforced concrete, each 13 ft. long and 8 by 11 in. in cross-section, have been made, and, in connection with the investigation of the behavior of these beams, nearly 3,000 tests have been made. Nearly 900 of these beams, probably more than double the entire number made in other laboratories in the United States, during a period of more than 15 years, have been tested. In the section of building blocks, 2,200 blocks have been tested, including, with auxiliary pieces, more than 4,500 tests; also, more than 900 pieces of concrete have been tested for permeability and shear. The physical tests have numbered 14,000; tests of steel for reinforcement, 3,800; and 550 tests to determine fire-resistive qualities of various building materials, have been made on 30 special panels, and on miscellaneous pieces. [Illustration: Fig. 9. DOWN-DRAFT KILN] The tests of the permeability of cement mortars and concretes, and of water-proofing and damp-proofing materials, have numbered 3,470. The results of the work of the Structural Materials Division have already appeared in preliminary bulletins, as follows: No. 324, “San Francisco Earthquake and Fire of April 18, 1906, and Their Effects on Structures and Structural Materials”; No. 329, “Organization, Equipment, and Operation of the Structural-Materials Testing Laboratories at St. Louis, Mo.”; No. 331, “Portland Cement Mortars and Their Constituent Materials” (based on nearly 25,000 tests); No. 344, “Strength of Concrete Beams” (based on tests of 108 beams); No. 370, “Fire-Resistive Properties of Various Building Materials”; No. 387, “The Colloid Matter of Clay and its Measurements.” A bulletin on the results of tests of reinforced concrete beams, one on the manufacture and chemistry of lime, and one on drying tests of brick, are in course of publication. FUEL INVESTIGATIONS. The scope of the fuel investigations has been planned to conform to the provisions of the Act of Congress which provides for analyzing and testing coals, lignites, and other mineral fuel substances belonging to the United States, or for the use of the United States Government, and examinations for the purpose of increasing the general efficiency or available supply of the fuel resources in the United States.