the measurement of temperatures in gas producers, in the furnaces of
steam boilers, kilns, etc. The work includes determinations of the
thermal conductivity of fire clays, concrete, and other building
materials, and of their fire-resisting properties; measurements of the
thermal expansion and specific heats of fire-bricks, porcelain, and
glazes; and investigations of the effect of temperature variations on
the various chemical processes which take place in the fuel bed of the
gas producer, boiler furnace, etc.

The heat laboratory is equipped for the calibration of the thermometers
and pyrometers, and electrical and other physical apparatus used by the
various sections of the Technologic Branch.

For convenience in analyzing materials received from the various
purchasing officers attached to the Government bureaus, this work is
housed in a laboratory on the fourth floor of the Geological Survey
Building in Washington.

Large quantities and many varieties of building materials for use in
public buildings under contract with the Supervising Architect’s office,
are submitted to the laboratory by contractors to determine whether or
not they meet the specified requirements. Further examinations are made
of samples submitted by superintendents of construction, representing
material actually furnished by contractors. It is frequently found that
the sample of material submitted by the contractor is of far better
quality than that sent by the superintendent to represent deliveries.
The needed constant check on deliveries is thus provided.

In addition to this work for the office of the Supervising Architect,
similar work on purchases and supplies is carried on for the Isthmian