Evening star., 1942-03-21
Of Stors, Men
And Atoms
Notebook Of Science Progress
In Laboratory. Field
And Study
By Thomas r. Henry.

| By Thomas r. Henry.
| Government chemists in the past two
months have developed what Is believed
to be the most adequate defense against
fire bombs
But when they proposed to conduct
critical tests Of the device few weeks
ago they learned that scrap of paper
probably blocked the way.
This is patent No. 2.232 sos. issued in
1941 to George Harald Dunston, Wolf
gang M. Herman, Max r. Land and
Werner Blyberg of London.
The same patent was issued by the
British government in 1898. before there
was any conception of the importance
OF fire bomb defense. Apparently the
device, which is relatively simple. never
| has been made use Of in England.
Thus from one point OF view scrap
Of paper stands between the American
public and what the chemists consider
valuable defense weapon.
From the viewpoint of patent Office
officials. however. this is unjust since.
they hold, the publication of the patent
lIldOS tllc lIllOl IldtlOll dfdlldDlC W tllC
American people anyway. and 1t was
pure coincidence that Government scien-
lists hit on the same thing.
The device is simply $3.50 mixture
OF some fusible material in powdered
form, preferably tar or resin, with any
non-fusible inorganic material such as
sand The material recommended by
the inventors is powdered slate. The
sand or slate would prevent the powdered
tar from melting and becoming sticky
mess at ordinary temperatures 1t also
would prevent 1t from catching fire
easily and would take up some of the
heat from the magnesium.
The patent, officials at the Patent
once explain, could not stand in the
way OF the Government itself.
Under the law the Government could
tured by anybody and make a reasonable
settlement with the inventors later. No
injunction proceedings can be brought.
The Army or the Navy also are author
lied to purchase any patent rights and.
If the patentee refuses to SELL proceed
to let it's contracts.
This particular device, however, would
have a limited use for purely military
or naval purposes and would chiefly be
valuable for civilian defense. An in
dividual would not be entitled to make
any of the mixture, even for his own
protection and to be rendered available it
probably would have to be manufactured
under Government order and distributed
through Government agencies.
According to one source of informa-
ton, the patent is extremely broad and
apparently would be violated by the mix
ture of any fusible organic material with
any non- -fusible inorganic material. So
far as known, the English inventors have
not been approached. The device may
simply have been overlooked in Great
Britain
Instructions usually given AFRAID
wardens and fre-fghting units all over
the United States are that pals Of sand
should be kept handy to be shoveled on
fire bomb as quickly as possible. This.
however, does not put out the fire. 1t
simply localizes it so that 1t will burn
out where it lands or make it possible
to pick it up with a shovel and get it
away from any other inflammable ma.
terial
Instructions are to avoid spraying the
bomb with water The burning magnes-
ium simply unites with the oxygen in
the water and makes hotter fire. AS
result millions Of pals Of sand are
distributed through Office buildings, fac
tories and apartment houses.
The advantage of the powdered tar
or resin is that a shovelful thrown over
a burning bomb melts quickly in the
intense heat and forms an airproof
blanket over the whole mass. Deprived
of oxygen, the fire is extinguished al
most instantly.
A few months ago something very
similar was announced by the United
States Bureau of Mines 1t proposed
using only faxed pitch, which would not
violate the patent since nothing was
mixed with it. 1t was Of type, how
ever, which melted only at fairly high
temperature Otherwise it hardly could
be kept in faxed form. In an emergency
there might be only sticky mass which
could not be shoveled.
The powdered slate or sand would ef-
fectively prevent such fusing. except at
very high temperatures--far above those
to be encountered in any building.
Powdered slate in particular, the in
ventors say In their patent application.
has an enormous capacity for taking up
heat, thus reducing the heat of the fire
itself.
1t is noteworthy that the patent soft
pedals" the possible military utility. 1t
stresses the value of the mixture in fac
tories where magnesium or aluminium is
being machined and where fires may
break out as a result of friction with
grinding or cutting wheels.
The cost of such a mixture, Govern
ment scientists have estimated, would
be about a cent a pound.
But apparently no private individual
can make any Of it-as the case now
stands.
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should like to offer you my congratu-