Evening star., 1950-08-02
New Explosion Camera
Developed at Aberdeen
Will Take 100 Million
Pictures in Second
By Thomos R. Henry

A camera that will take 100 million
pictures a second has been developed
for the Army.
It is being used at the ordnance prov
ing ground at Aberdeen, Md, to photo
graph explosion waves moving through
the air at velocity of about $4,000
miles second.
The new camera Is expected to help
materially in the design and develop
ment of weapons and it also may be put
to use to study detonation knocks in in
ternal combustion engines.
Made From Scrap.
This camera was made partly from
scrap equipment and odds and ends in
the laboratory at Aberdeen The total
cost is estimated at less than $500. 1t
was designed by Morton Sultanoff a
civilian employe at the proving ground.
An explosion, Ordnance Department
experts explain, has definite, well-or-
dered pattern from detonation to shock.
Although the period involved is measured
in millionths of second the velocities
of these phenomena are as much as a
quarter of an inch in millionth Of
second.
The ultra high speed action is OBJ
tanned by use of framing grid and ro-
tatlng mirror The framing grid is a
focal plane shutter which consists of a
series Of parallel narrow Sits cut at uni
form intervals through an opaque plate.
The width of the slit determines the eX-
posure time and the ratio of space width
to slit width determines the number of
successive independent frames which
will be taken.
Possibilities of even greater speeds are
envisioned if there is need of improv-
ing the present somewhat crude design,
but these are not called for in the pres
ent studies.
A new series of shining, rust
resistant hard metal alloys in which
phosphorus is combined with cobalt or
nickel is being developed by United
States Bureau Of Standards physicists.
They promise to replace chromium to
some degree as a plating material for
automobile parts, kitchen utensils and
the like
According to Bureau announcement.
they are more easily deposited than
chromium. They provide both hard,
wear-resistant surface and decorative
finish and the electroplating process is
simpler than that used with chromium.
The appearance of the alloys depends
on their phosphorus content. Alloys with
less than two per cent of this element,
which is not included among the metals,
are usually smooth with a mat finish.
but as the percentage of phosphorus in
creases they become brighter until A.
nally they become nearly as lustrous az
the most shining nickel.
Possibilities for Designs
When some of the phosphorus alloys
are immersed momentarily in a solution
of an oxidizing agent jet black film is
formed on the surface of the metal. This
film is hard and adherent and appears
to have possibilities for decorative de-
signs.
The new alloys, it is emphasized, can
be tailor-made for the specific purpose
to which they are to be used. 1t all de-
pendS on the amount of phosphorus
mixed with the nickel or cobalt.
At the same time the bureau metal
lurgists are exploring the possibilities Of
alloys of magnesium, almost the light
est of the usable metals, to determine
strengths and rust-resistance. These
differ greatly, the experiments have
shown, with the amount Of moisture
in the atmosphere and many other fac
tors. Use of magnesium to partially re-
place aluminium in aircraft manufacture
was a major problem in the last war.