Evening star., 1938-12-27
Of Stars, Men
And Atoms
Notebook Of Science Progress
In Field, Laboratory
And Study
By Thomas r. Henry.

And Study
By Thomas r. Henry.
The south side Of building in this
latitude annually receives four and one
half times as much sunlight as the north
side-360O hours to 300 hours.
This was determined by measurements
recently made in New York City by Frank
Benford and John F.. Beck, General Elec-
trio Co. engineers. They devised a for
mula by which, knowing the compass
direction of building together with its
latitudinal and longitudinal location, it
is possible to determine accurately with
in four minutes the number Of hours the
sun annually will enter given window.
They also found that anybody looking
for the utmost possible sunlight in the
course of year should live at the North
or South Pole, not at the Equator.
Either pole receives, they found, 65 hours
more sunlight year than is received in
the tropics. The explanation is that the
suns atmosphere refracts the suns rays,
so that the sun is visible even when it is
below the horizon. At the Equator this
increase amounts to 40 hours year,
compared to los hours at the poles.
The study will make it possible, the
engineers point out, for architects to
plan such rooms as sun porches, So
lariums and sleeping porches with a
more exact knowledge of the sunlight
directed at any particular area Air
conditioning engineers also will be able
| to use the study in determining the
amount of solar heat energy received in
a room and make proper provisions for
| heating or cooling it.
The Smithsonian Institution now Is
setting up new observatory on the
8,O00-feet-high summit of Burro Noun
tain, near the village of Tyrone in ex-
treme Southwestern New Mexico-one
OF the dryest, clearest spots in the United
| States from which to measure daily vari-
ations in the radiation of the sun.
At this observatory will be installed
the apparatus used by the Smithsonian
| observers at the observatory on the
Sinai Peninsula, which was closed last
| year. In many respects an ideal spot for
Eastern Hemisphere observations of solar
| radiation, the isolation of the peninsula
and the extremely forbidding environ
| ment led the institution to close the
observatory there after very successful
record for four years.
Alfred P. Moore, who had been in
charge of that station, returned to the
United States this spring and imme-
diately started his search for a suitable
American station. The ideal spot is one
IN which there is minimum of cloudi-
ness and rainfall, together with a very
clear atmosphere usually to be attained
only at great heights. Meteorological
records show that Burro Mountain has
approximately 10 inches of rainfall
year. This in itself is small, but there
is the additional advantage that it is
nearly all concentrated in the months
OF July, August and September. A
cloudy day is an extreme rarity at any
other season. In contrast to most of the
stations occupied by Smithsonian astro-
physical observers, this is very pleasant
spot, according to Secretary Charles G..
Abbot, who has just returned to Wash
ington after inspecting the progress of
the work. There are small trees. shrub
berry and flowers on the mountaintop,
There is an excellent source of water
only miles away and it is planned to
build a large reservoir tank on the
summit itself.
The observing instruments, including
some of the most delicate and sensitive
known to astronomy, will be located in
horizontal tunnel extending back for
approximately 80 feet into the mountain.
The sunlight will be reflected into this
tunnel and upon the measuring instru-
ments by mirror. The excavation of
this tunnel now is completed. Living
quarters are being built for the observers
and their families.
The work of the observatory, in COM
mon with that of other Smithsonian
astrophysical stations, will be to deter
mine daily variations in the solar con-
stant-the average amount to which a
black body l cubic centimeter in dimen-
sions would be heated by the rays of the
sun falling upon it in minute, pro-
vided it was located at the mean solar
distance and at the outer limits of the
earths atmosphere. In actual practice,
OF course, no such direct measurement
can be made, but the same result can be
obtained with the use of extraordinarily
delicate measuring devices when proper
allowance is made for the effect of vari-
GUS thicknesses of atmosphere on sun
light passing through it.
The Smithsonian Institution has gath
cred an enormous number of such daily
records. They show clearly that the heat
and light output of the sun constantly
is fluctuating, and that these fluctua-
tions follow periodic curves. There is
excellent reason to believe that these
fluctuations in turn, are major element
in the fluctuations of temperature and
precipitation on earth. The subject,
however, Is extremely complicated and
constant observations, together with a
constant effort to make them more and
more accurate, are essential.
Questions Efficiency Of