Measures for Progress: A History of the National Bureau of Standards

IN THE EVENT OF WAR 373
A mockup mask devised at the Bureau for cutting the upward glare of sealed beam
headlights, one of dozens of such blackout or brownout devices to reduce skyglow over
the coastal cities in the first years of the war.
In the spring of 1942 the Office of Civilian Defense instituted dimouts
and blackouts in full force. At the request of OCD, the Bureau tested textiles
and paper as blackout materials, devised masks to eliminate upward light
from automobile headlights, improved Army blackout headlamps, and deter.
mined the acoustic properties of suitable air-raid alarms, including sirens,
steam and compressed-air whistles, and loudspeakers. A Bureau letter cir-
cular went out to city and town authorities on alarm systems they might set
up with available materials, and an "Air Raid Protection Code for Federal
Buildings" was distributed to Federal offices throughout the country.25
The construction of Army camps, bases, and temporary Government
office structures that began with passage of the Selective Service Act went
into high gear after 1941. The Bureau's building specifications for their
fabrication saved much vital material. (Labor costs were something else
again.) In the stress of the emergency, glaring deficiencies in building codes
that had resisted Bureau efforts at change were rectified by Federal edict,
25 NBS Annual Report 1942, PP. 110, 115; Lyman J. Briggs, NBS War Research: the
National Bureau of Standards in World War II (September 1949), pp. 103—104 (here-
after cited as NBS War Research) ; LC685, "Devices for air raid warnings" (1942),
superseded by LC706 (1942).