The San Francisco call., 1897-05-16

are warm, though not oppressive, because
vision during the day is usually unsteady
on account of air currents which rise from
the neighboring canyons and from the
heated rocks Immediately bordering the
plateau OF the summit.
The large valley of Santa Clara lies all
day long in the ardent sunshine. Late in
the afternoon the sea fog begins to creep
in through the various gaps in the Coast
Range, which borders the Santa Clara
Valley on the west, and to come toward
the north from Monterey Bay through
the valley of the Pajaro River. A local
fog from the bay of San Francisco often
sends its thinner wells toward the south,
but seldom penetrates as far south as
Giiroy. where the Monterey fog is entering.
Up to this time the fogs are low lying.
AS the afternoon goes on, the sea fog rises
higher and higher and often pours over
the tops of the highest peaks of the Coast
Range that tower 3038 feet, completely
covers the valley Of Santa Clara and fills
the neighboring canyons, although it
seldom rises to the observatory's level,
being usually thousand feet lower. Thus
the scientists at Lick Observatory are
above the clouds and gain news from the
heavenly bodies while they, to the ma
jority of persous, are invisible. Once in
while the fog covers the summit Of
Mount Hamilton, but only about as often
as the equinoctial storms come.
Harvard College observatory. of which
we have already learned through the
South American chain OF stations, has a
meteoroiogica observatory on Pixies
Peak, IA, 1874 feet in altitude. For fifteen
years this station was continually occupied,
but now the observations are generally
confined to the summer months. A nota.
BILE feature of the Pixies Peak observatory
is the fact that the most tremendous elec-
trical storms, which occur in North Amer
ica seem to cluster about its sum NIT. The
lightning is nearly continuous for long
periods, and the deep rolling thunder is
shattering to the strongest nerves.
The observers on the mountain summit,
although much in commoded by these
electrical storms. have learned how to ar
range their instruments SO as to avoid all
real danger. 1t was from this point, in
| July, 1878, that DR.. Langley observed the
total solar eclipse. Other observatories of
note on this continent are those of
Flagstaff, Ariz., 1900; Echo Mountain,
Cal, $500 feet; Chamber Observatory,
in Denver, Colo. 5400 feet; the National
Observatory of Mexico, at Tacu5aya, 1900
feet.
No observatory exists around which
m ore interest clusters than that at Mont
Blanc, which rears its snowy head Is 7S0
feet from the surface of the ocean. The
| story of this observatory. of the dangers
of those who have utilized it, are succeed
| ing chapters in the tragedy of human ex
istence such as science cannot elsewhere
produce. This observatory was erected
| by NJ. Jansen upon compressed snow, be-
cause no rock foundations were available
| 1t is provided with jackscrews, in order
that it may be leveled if necessary.
The base of the structure is 10 bv 5
meters and the snow always covers the
| lower story 1t was the intention to leave
the upper story in free air, ana during OBJ
servation a telescope is mounted in an alu-
minum dome above the upper story. The
construction is very solid and strong, with
double walls and floors. and no pains have
been spared to make it safe and rigid. As
an indication of the character of the founda-
| tion of the observatory, tunnels were run
| thirty-six feet below the surface without