Evening star., 1948-12-29
Stars, Men and Atoms
Sun Furnace to Be Built
By Naval Research Office
Experiments With High Heat Planned
to Produce Synthetic Materials
By Thomas r. Henry


sun furnace, which in theory can con-
centrate the temperature Of the suns surface
on a space about three inches in diameter, ts
among the projects Of the Once Of Naval
Research.
A contract for constructing such an apparatus
has been given to Rockhill College at Kansas
City where the work will be carried out under
the direction of Dr. William Conn.
The furnace consists essentially Of q mirror
feet in diameter which will focus all the
solar radiation from q large part Of the sky.
An apparatus also is being designed by which
the mirror automatically will follow the course
Of the sun across the heavens.
Such q device, 1t Is explained by naval
scientists, offers great advantages In several
fields of research. Similar intense temperatures
might be attained by other means but they
would require fire container Of some sort
and the resulting heat would be contaminated
by various chemical vapors.
5000 Degree Heat.
BY mathematical calculation 1t should bs
possible to concentrate on q small surface Q
heat of approximately 5000 degrees centigrade,
sufficient to melt any metal or alloy known
on earth. 1t is highly doubtful, however, If
such temperature could be reached in practice
except on an extremely clear day with no
absorption of heat by clouds. Turning refrac-
tory ores to vapor Is one Of the essentials Of
some Of the Navy's efforts to produce synthetic
materials
There have been-experiments with sun fur
naces for some time in Europe, it was explained,
but the development has been held back by
details difficult to overcome. This represents
the first major attempt Of its kind In the
United States.
A pilot plant for production Of synthetic
mica, strategic war material for which this
country hitherto has depended almost entirely
on imports, has been set up by the ONCE Of
Naval Research and the Army Signal Corps
at Norris, Tenn.
Successful synthess Of this material on a
laboratory scale was first accomplished at the
Colorado School of Mines few months ago
and the pilot plant work, to determine whether
commercial production Is feasible, is under the
Interior Departments Bureau Of Mines. II
the experiment proves successful, 1t is expected
to make the United States elf-sufdcient in
material that is the mainstay Of electrical
insulation
Mica, as mineral, Is scattered widely
throughout the world. There are some small
deposits in this country, but despite Govern
of the amount needed was produced here in
the critical years of 1943 and 1914. AL the
rest was imported from India, Brazil and
Madagascar.
Handicap for Germany.
Lack Of mica was serious handicap for
Germany in the First World War and inmedi-
atey after the armistice efforts were launched
to produce synthetic product. These met
with Indifferent success until about ten years
ago when they appear to have been quite suc-
cessful. The American experimentation, how
ever, was undertaken quite independently Of
the German accomplishment, Of which full de-
tails were available.
The Importance of the project is indicated
by the fact that several grades of mica have
been designated as Class-A strategic materials
under the recently enacted Stockpiling Act.
A synthetic material has been prepared which
has all the insulating value Of natural mica
and at the same time can be split into very
thin sheets This has been exceedingly difncult
with any domestic natural material.