the Supervising Architect, or the great 4,500,000-bbl. contract of the
Isthmian Canal Commission, are made in the cement-testing laboratory of
the Survey, in the Lehigh Portland cement district, at Northampton, Pa.

_Testing Machines._--The various structural forms into which concrete
and reinforced concrete may be assembled for use in public-building
construction, are undergoing investigative tests as to their compressive
and tensile strength, resistance to shearing, modulus of elasticity,
coefficient of expansion, fire-resistive qualities, etc. Similar tests
are being conducted on building stone, clay products, and the structural
forms in which steel and iron are used for building construction.

The compressive, tensile, and other large testing machines, for all
kinds of structural materials reaching the testing stations, are under
the general supervision of Richard L. Humphrey, M. Am. Soc. C. E. The
immediate direction of the physical tests on the larger testing machines
is in charge of Mr. H. H. Kaplan.

Most of this testing apparatus, prior to 1909, was housed in buildings
loaned by the City of St. Louis, in Forest Park, St. Louis, Mo., and the
arrangement of these buildings, details of equipment, organization, and
methods of conducting the tests, are fully set forth in Bulletin No. 329
of the U.S. Geological Survey. In brief, this equipment included
motor-driven, universal, four-screw testing machines, as follows: One
600,000-lb., vertical automatic, four-screw machine; one 200,000-lb.,
automatic, four-screw machine; and one 200,000-lb. and one 100,000-lb.
machine of the same type, but with three screws. There are a number of
smaller machines of 50,000, 40,000, 10,000, and 2,000 lb., respectively.

These machines are equipped so that all are available for making tensile