Photographic History of Table Mountain
Observatory
Part 2: Site Buildup: Local Area
& Solar Constant Research
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.
Let's first look at the
beginning site and buildings that Smithsonian constructed in the two
years
from 1925 to about 1927. You can refer to the 1925 map above to
show their placement on the
grounds at the very top of Table Mountain. There was never any
indication of what was the first
built, and no attempt is suggested by the following order.
This is the original director's
residence with fireplace. The assistant director's residence is seen to the left . SIA
This became the shop and studying
building for the scientific results of Smithsonian's solar constant measurements. SIA
This was a temporary garage for
the site's winter snowplow. SIA
This is the assistant director's
residence. SIA
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 late
1925. Mr. Moore became the
first 'field' director for this site. LAPD
The original 1200 gallon water
tanks (a second
one is directly behind the one in front). Water was
pumped from the valley
floor where an
existing well was already in use. SIA
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.
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. Unknown source.
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. Photo courtsey of Rich McCutchen.
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. SIA
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. SIA
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. SIA
The new Table Mountain bunker (tunnel) setup in 1926. SIA
The bunker in wintertime. SIA
Researchers using the instruments at the bunker. 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
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
Instrumentation
inside the bunker. There was no description of what these items
were. SIA