(4).--The best and most economic methods of protecting steel by
fire-resistant covering.

(5).--The most efficient methods of proportioning and mixing the
aggregate, locally available, for different purposes.

(6).--The character and value of protective coatings, or of various
mixes, to prevent deterioration by sea water, alkali, and other
destructive agencies.

(7).--The kinds and forms of reinforcement for concrete necessary to
secure the greatest strength in beams, columns, floor slabs, etc.

(8).--Investigation of the clays and of the products of clays needed in
Government works, as to their strength, durability, suitability as
fire-resisting materials, and the methods of analyzing and testing clay
products.

(9).--Tests of building stones, and investigations as to their
availability near the various building centers throughout the United
States.

The operations of the Structural Materials Division include
investigations into cement-making materials, constituent materials of
concrete, building stones, clays, clay products, iron, steel, and
miscellaneous materials of construction, for the use of the Government.
The organization comprises a number of sections, including those for the
chemical and physical examination of Departmental purchases; field
sampling and laboratory examination of constituent materials of concrete