The record-union., 1897-10-15
ON MOUNT TAMALPkIS.
ESTABLISHMENT oF A METEOR.
ILLOGICAL STATION THERE.
Important Discoveries Made by
United States Weather
Bureau officials.

Pacific Coast and to travellers from all
over the world merely a point from
which a wonderfully beautiful pano-
rama of sea and bay, mountain and val
ley, city and town could be viewed. Ly-
ing within two hours travel of San
francisco, the mountain has, in
way, been merely a pleasure ground
Tamalpais will always be a pleasure
ground. But it will in the future be
something more than this. 1t is pro-
posed to erect and maintain on this
summit a meteorological observatory,
Where Will be determined important
data of meteorological observations,
namely, the temperature, pressure, hu-
nudity and electrical potentiality of the
air; the rate of evaporation; the
amount and kind Of precipitation; the
direction and velocity of the wind; the
kind, direction of motion and velocity
of clouds; the duration Of sunshine and
the intensity of solar and terrestrial ra-
diation. This data viii for the most
part be determined by self-registering
instruments, and will be preserved for
comparison, reference and study, with
view to using the knowledge gained
for forecasting.
Many Of these self-registering instru-
ments are even now in position and at
work. They are in the hands Of Alex
ander McAdie of the Weather Bureau,
detailed for the work by Mr. Harmon,
forecast official
So far very little expense has at
tached to the Mount Tamalpais wealth
er station. In fact, the amount ex-
pended ie something less than $1,000.
An thermometer, or wind gauge, has
been placed on the mountains topmost
point. This instrument determines the
velocity and pressure of the wind.
Above this instrument is the weather
vane to indicate the winds direction.
These instruments are connected by
wires through lead pipe with electro
cal machines in the office little farther
down the mountain, where the records
are made
Some remarkable data has been col
lected by both Mr. Harmon and Mr..
McAdie with the thermometer. During the
month of September the totalVelocity Of
the wind exceeded 12,000 miles, and
over 5000 miles was from the north
west. 1t was also ascertained that
whenever the wind reached velocity
of 10 miles an hour or more rain was
sure to follow somewhere in the north
ern part of the State At different times
during Mr.. Hammons stay on the
mountain last month the wind reached
a velocity of 1000 miles a day. At
this rate it would require only three
days to bring a vast volume Of air from
the Alaskan snow fields to the orange
groves of California Such an indraft
of air usually, though not always, fol-
lowed a period of hot weather, and the
heavy cold air from the north rushed
in to fill the vacuum made by the neat
ing and consequent expansion ana rare
fcatfon Of the atmosphere.
Down under the awning Of the tavern
IS an instrument shelter, in when are
fo1lr thermometers and a thermograph,
which records temperature. Mr.. HAM
mon made a notable discovery with this
latter instrument. The normal condl-
1ion prescribes that the higher the
altitude the cooler the weather. ms
condition was for two weeks at a time
completely reversed on Mount 1aih-
alpais. and while San Franclscans We're
wearing their furs and oVercoats' II
was 20 degrees warmer on the mount
ain.
The Weather Bureau has an once
on Mount Tamalpais in when are MI.
MsAdie's desk and chair, the tapie oii
which the the several registering
electrical machines, together with maps
and other necessaries of the statloh'
The walls are rough boards so loosely
nailed that the cold air at times Whlris
through unpleasantly.
The sun instrument or solar radiation
register. which was shipped to the
mountain. though carefully packed ana
handled. was broken. So no record mas
beer. secured of the suns intensity or
time of shining. A pluviometer, com
monty known as a rain gauge, has been
placed on a high point near the ofhce-
Now only one other instrument is lack
ing for practical work by the station
after the sun instrument shall have
been repaired and put in place, ana
that a seismograph TO register earth
quake movements.
That Mount Tamalpais is an ideal
snot on which to erect an observatory
both for meteorological and astro-
nomical purposes-cannot be question
ed The nearness Of the mountain TO
our two great universities, its accessl-
bility and its hight contribute TO its
desirability as an ideal meteorological
station. Fog rarely rises above the
apex of the peak, and the sun is sell
dom obscured.
Mount Tamalpais is, perhaps, the one
high pOint near San Francisco above
all disturbing influences of local con-
di+ions. In San Francisco wind direc-
tions are influenced greatly by the sur
rounding hills. Then, too, there is eV-
ery afternoon and night a steady in
flow OF wind from the sea, purely To-
cal and due to the intense heat of the
interior valleys. This wind is usually
as all San Franciscans know, heavily
laden with fog. On the summit OF
Tamalpais and completely removed
from these local disturbances the OBJ
server can watch changes and condi-
tions that he could not discern in San
Francisco. For instance from the peak
clouds which produce and accompany
local valley showers can be seen and
their courses followed even when they
are 100 miles away Smoke and dust
would render this observation impos-
sible at even a shorter distance if the
observer were at a lower elevation. In
the same way vessels can be observed
entering port two or three hours be-
fore they are sighted at Point Reyes
or Point Lobos.
Mr.. McAdie has secured a variety OF
cloud photographs from the mountain
top. Several of these are so beautiful
as to be sought by meteorologists in
other partS of tha world