Evening star. [volume] (Washington, D.C.) 1854-1972, 1930-04-27

From such scientific niceties as de-
| ternining variations of l in 100000
in measurement units to the resistibil-
! ity of roof paint to the weather. the
| scope and range of the work of the
| Bureau of Standards continues unin-
| terruptedly. ferreting out facts which
| to the layman seem of very remote
| value on the one hand or very prac-
| tical on the other. To the technicians
| in charge of the bureaus work all
| experimentation is Of ultimate value.
Recent work of the bureau has been
in connection with establishment of an
| international standard for the joule, a
unit of heat measurement. and Of the
watt, measure of electricity. It APP
pears that, while there is a so-called
international unit for most of these
measurements, it is not absolutely pre-
else, various countries, in their local
mechanical application, showing some
variation. This variation is so slight
that to the lay mind it is wholly
negligible. But precision Is the es-
sence Of Bureau of Standards work
and the same relates to the British
National Physical Laboratory and to
the comparable bureaus of other ma
tons.
In such a work as the present in
vestigation the first step is to determine
how far off each national standard is
from the international one. Precise
knowledge on this point makes precise
| conversions possible when it is desired
to translate a measurement stated in
terms of international joules or watts
| into national ones.
While 1t is doubtful whether the
news will come as a shock to the
ordinary reader nevertheless the bu-
| reau has determined that our national
ohm is oversize in relation to the
international ohm by as much as S in
10000. Moreover, our volt is too big
by As parts in 100000. AS volts and
ohms influence joules and watts, it
becomes important to track down the
whole series Of variations. The answer
is that the joule is too large by 4
parts in 10000, and so it warns all
users of joules that to be accurate in
their calculations conversions should
be made in the ratio-1 international
equals 10000 local mechanical units.
Improving Radio and Aviation.
The bureau is continually searching
out the mysteries of radio. An investi-
cation now IN progress Is designed TO IND
out what happens to radio impulses be-
tween the instant they leave the trans
hitting station and their arrival at
receiving station. Already it has been
determined that part of radio i'm
pulse leaps upward and is echoed back
from a sort of ceiling of upper atmos-
phere before proceeding on its way.
This part of the impulse is retarded by
its longer journey sufficiently TO be
noted by fine instruments and might
| possibly result in confused or blurred
signals, although the retardation is very
| insubstantial.. At 1880 o'clock in the
morning the echoed radio wave is
| .00l43 part of a second behind the
ground wave and at pm. it is .00l53
part of a second late. This is on
| frequency of 4,045 kilocycles. During
magnetic storms and at night the de-
| lay is greater. However. no one would
ever miss train by being .00l43 part
of second late.
Experimentation to devise radio an
tennas for airplanes which will over
come the difficulties encountered by
| formation of ice upon those now en-
| ployed Is being carried on by the bu-
reau. It also is making laboratory tests
TO perfect radio direction finders to as
sist in aerial navigation. While in
volving the closest scientific calcula-
tons. this work has practical value to
| flyers.
| There is scarcely an adult reader of
this or any other newspaper who has
not tucked away somewhere one or
more newspaper clippings. If the coll
| lection is large and covers a consider
able span of years, the owner doubt
/ less has wondered why 1t is that many
of the older clippings appear to be bet
ter preserved than those of only a few
years ago. The Bureau of Standards
| has gone into this matter. Obtaining
from public library files samples of old
newspapers, it has made tests to deter
mine what the paper used was made of
| and arrive at conclusion as to the rea-
| sons for deterioration.
group OF newspapers ranging in
date from 1866 to 1873 was found to
be made up Of specimens in excellent
| condition, where latter group ranging
from 1874 to 1880 showed marked de-
| terioration; so much So in fact, that
| the paper would crack on being folded
but once. Analysis revealed that the
earlier samples were made from chemi-
cal pulp fiber produced from rags, eS-
parto grass, straw, and wood. The in
| ferior specimens we're made from a
cruder groundwork fiber mixed with
chemical fibers.
A Peep Into Laboratories.
The conclusion reached was that lack
| of proper publication of the fiber is re-
sponsible for rapid deterioration. The
| rag content did not seem to govern.
| The paper in good condition in some
cases had as high as 80 per cent rag
content, but, on the other hand, very
badly deteriorated paper had up to rs
per cent rag content. Certain modern
paper making processes had not come
into use when the earlier samples were
| made.
The bureau has Just taken down from
the roof of one of its buildings samples
of roof paint, which had been placed
there for experimental observation six
years ago Wood panels and metal pam
els had been painted with roof paints
of various mixtures, various pam
els having a different number of coats
of paint. The purpose of the expert
ment was To determine the resistance of
certain types and mixtures of paints
to sun, rain and other vicissitudes of
weather. Some samples checked and
peeled and faxed badly and Others