A
Photographic History of Table Mountain
Observatory
Part 2: Smithsonian Field Station
Buildup at Table Mountain;
Solar and
Astronomy Research Conducted - 1925-1962
By James W. Young
retired astronomer from Table Mountain Observatory By the late fall of 1925, Table
Mountain had the necessary buildings, equipment, instrumentation,
and staff to begin their full solar research programs for this newest
field station. Equipment from
Mt. Harquahala had been transported to Table Mountain, and Harquahala
was phased out of the
active Smithsonian stations.
This is a reconstructed
drawing of the original Smithsonian building placement at Table
Mountain. Drawings and site plans made by
and after JPL acquired the site in 1962, were used to produce this rendition of the exact
position of these buildings, and additional renditions will show further developments throughout
Smithsonian's occupancy, all to the same scale.
Although not a part of Table
Mountain, the 'Big Pines - L. A. County Camp' (also known as the 'Big Pines Recreation Camp) was used
in the 1920s and 30s by Smithsonian for supplies and the mail. In fact, this area actually
became the town of Swartout (later correctly spelled as Swarthout).
The Recreation camp and Swartout became a bustling business for skiers,
tobogganers, and even
ice skaters in the winter, along with camping and outdoor recreational
activities in the summer.
The road from Wrightwood to the
Big Pines Recreation Camp. Unknown source.
View of Big Pines looking west. Unknown source.
The 'camp' snowplow clearing the
parking area of fresh snow. Unknown source.
The dedication of the Davidson
'Arch' in 1926. LAPL
The Table Mountain Road where it
joins the road junction at Big Pines. FF
Snowplayers and vehicles at Big
Pines. Unknown source.
Parking at a premium; looking east
from the bottom of the Table Mountain Road. LAPL
The 'playground' with the Table
Mountain Road in the background. USC
The Table Mountain Raod up from
Big Pines.LAPL
The campground for summertime
vacationeers. Unknown source.
The
original sign at the Swart(h)out
Post Office. RM
Most communications between the Table
Mountain field station and Smithsonian in
Washington DC
were done by mail, but there needed to be a faster method of reporting
data back 'home'. Soon,
negotiations were completed in 1926 for a telephone line to the
recreations camp area; from the
camp to
Wrightwood, down Lone Pine Canyon to Keenbrook, and on into San
Bernardino. Nearly all
of the following material (documents, drawings, and pictures)
came courtesy of the Smithsonian
Institute Archives (SIA),
with those others credited accordingly.
Communications between the field station and
Washington DC soon became possible
with this new line, at least from Swartout. It
wasn't until 1935 that an actual line was
made from the camp to Table Mountain itself.
We will now look at the history
of the various buildings that Smithsonian utilized during their 36 year
occupany of Table Mountain. The building construction dates, who
built them, and where the building
materials came from was poorly documented at best. From record
inspections of the Arizona field
station at
Mt. Harquahala, only equipment was transported to Table Mountain.
It is very likely most
of the building materials came from local sources, and in some cases
was used timber (when one of
the original Smithsonian buildings was torn down in the 1970s, several
'stud' pieces showed signs of
prior use, just as was found by current owners [ABM] of McClellan Flat
buildings in 2010).
After the Jet Propulsion Laboratory acquired the site from Smithsonian
in 1961, all then current and
future buildings were deginated by a simple number system; ie, 1-29,
which is still in use today. For
the sake of clarification throughout the remainder of this historical
material, these numbers will be
used as necessary to distinguish individual buildings, especially since
many transistions, modifications,
and removal of many took place after 1962. This will aid the
reader as the history continues into the
21st century. Furthermore, these numbers were started in 1962
after the first 'JPL' building was
constructed, but extended to all buildings still standing on the
site. Therefore, understand that the
assigned numbers were/are NOT necessarily chronological in nature.
BUILDING 1 and 2 (see part 3)
BUILDING 3
During Smithsonian's tenure at Table Mountain, two
different partial underground 'bunkers' were
constructed to house various solar related scientific
instrumentation. The 'underground' purpose
was to help control the daily temperature fluctuations on the
instrumentation and their subsequent
readings.
The underground bunker, or tunnel
enclosure, was designed after the
successful use of them at
Montezuma and Harquahala.
The original 'bunker' hand
drawing. The following drawing was published in a Smithsonian
report found in the Smithsonian archives
material.
This was the first of 2 bunkers
built at Table Mountain; the second one was built in the early 1950s.
By placing the most temperature sensitive instruments inside the
bunker, accurate measurements
could then be compared and calibrated to data obtained at other 'field'
sites, with similar setups.
However, methods of calibration proved to be extremely difficult, and
it wasn't until Smithsonian
researchers found new methods to quantify their work that final results
could be published.
The excavation for the first bunker, with R. F. McClellan (L. A. County
Board of Supervisors) on the
left,
and Alfred F. Moore of the Smithsonian Institute, taken in 1925.
Mr. Moore became the first
'field' director for this site.
LAPL
The new Table Mountain bunker (tunnel) setup in 1926. SIA
The bunker in wintertime. SIA
Researchers using the instruments at the bunker. SIA
Additional instrumentation at the
first bunker. SIA
The coelostat and a Smithsonian
assistant and wife (presumed). SIA
Instrumentation
inside the bunker. There was no description of what these items
were. SIA
Two pyrheliometers on the right side, with a pyranometer in the
center. These instruments were
used to measure the solar irradiance (amount of radiation coming from
the sun), or flux density, in
watts/meter2.
The pyrheliometer made direct
measurements, whereas the pyranometer made
indirect (180O
field of view) measurements. Note these types of instrumentation
in the following
two photographs. SIA
A Smithsonian assistant using the instruments outside the bunker door. SIA
Smithsonian staff (and wife?) at
bunker. SIA
The full array of instruments at the Table Mountain bunker. Note
the mirrors in the foreground,
used to send a beam of sunlight into the bunker, and the more
temperature sensitive instruments. SIA
In 1952 a second bunker was
built just to the west of the first one, as shown in the following three SIA images
In this 1962 image, the number '3'
appears for the first time, as the numbering system begins.
BUILDING 4
A storage shed built
in the late 1930s for the assistant director's residence (building 5),
but
little is known about the use of this building.
1930s.
SIA
Sometime prior to 1961, some sort of
heating 'stack' vent was added to the west side of the roof, as is seen in the following two
images. 1961.JPL
Building
4 on the far left front, with Building 5 in the back center taken in
1962. JPL
The heating 'stack' vent was
later removed somewhere between 1966 and 1967. The entire shed along with Building 5 was
removed in 1974 in preparation for new building (#21). JPL End of Part 2
Part
3