The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1906-04-24
'SE|SMOGRAPH HAS
RECORDED No HEAVY
SHOCKS SINCE FIRST
No Entry of Sundays Quakes at San Francisco
Excepting Small One at II p. M.-.-How
Magnetic Station Is Equipped.

In a small, wooden, almost alright
little structure built upon a founda-
| ton of coral reef outcrop half way
between Eva sugar plantation and the
seashore on this island, the trenors
of Mother Earth are recorded, and
those which RACED San Francisco last
Wednesday, as we'll as subsequently,
have been traced infinitely and pho
togra phicalIy on a sensitized tape. The
tremendous shock of Wednesday caused
the pendulum needle to make terrific
gyrations across the tape On Friday
slighter shocks were recorded, and a
visit by an Advertiser man to the lit
the fact that at IL O'Clock Sunday
might still another light shock was reg
| istered.
| Dispatches from San Francisco on
had been felt. Both these items We're
received during the course of the aft
ernoon No such cuakes are shown
on the tape of the magnetic station
at Sisal.
! r. E Nyswander, in charge of the
| United States Magnetic Station of the
Geodetic and Coast Survey, developed
the tape after last Wednesdays earth
quake, and on Friday did the same for
the remainder of the tape up to that
time. Both Of these results have been
told in the Advertiser.
An Advertiser man went to the mag
netic station yesterday afternoon. Eva
plantation furnished him with a horse
and facilitated his efforts to obtain the
latest results. On arrival at the sta
ton Mr.. Nyswander was found in one
of the magnetic houses taking his
weekly figures of possible magnetic
variations in the dip of the earth to-
ward the North Pole. He was ire
mendously busy and had not heard up |
to that time of the dispatches from |
San Francisco announcing further !
shocks on the Coast. After finishing |
with the magnetic instruments, he
turned his attention to the Earth
quake House." which is some distance
apart 1t is a uueer-shaped structure.
1t is sunk into the coral reef couple
of feet so that the floor is perhaps two
feet below the surface of the ground.
1t is windowless save for one aperture
which is provided with a red glass
usually found in photogra piers dark
rooms. After passing through one door
the visitor finds himself in small
ante-room, with just room enough to
in Tho door closed
and then an inner door is opened. This
opens into the room where the tremors
IF the earth are recorded. In the dim
light which percolates through the
ed glass the outlines Of some dark
wood cases are to be seen, while the
ear is snitten with the regular tick
ack of a clock. A small lamp with
linn light stands upon the cover OF
he box beneath which is the delicate
pendulum which registers the quakes.
After shutting off the clock-work and
therefore, stopping the tape from NOV
ng on its constant way beneath the
pendulum, the red window is thrown
,pen and the castings of wood are re-
moved revealing the main instrument
There is a vertical metal post and
rom the lower part there projects
a long slender boom, the
nd of which is just above the sensi-
ICED tape. A tiny thread runs from
he outer end of the boom to the top
# the metal post. If a bit of canvas
we're fitted to the boom and thread it
1ight suggest the appearance of a toy
acht's mast and rigging.
The Instruments are known as the
fine Horizontal Pendulum. It's bear
1gs are hard steel points in order to
minimize friction, and the mountingS
re of the most accurate kind.
The outer end of the boom carries
thin metallic plate with a slit in it,
the end of the boom is
OK containing a roll of sensitized pa
err driven by clockwork. In the cover
the box is slit identical with the
slit in the pendulum so that beam
f light passing both Sits falls upon
lie Photographic roll of paper tracing
sinuous line as the boom moves
ght or left This beam of light falls
pom a mirror and is reflected by that
trough the first slit and falls upon
.e slowly moving ribbon.
The boom is four feet long and car
es a sliding weight. 1t has a cup
quartz at the inner end which rests
pom a hard steel point set in the up
ght steel post
The whole apparatus is enclosed in
OGDEN boxes to shield it from air
lrrents, which have an effect upon
lie pendulum.
The instruments are placed to point
nth and south and so take mainly
rocks which are east and west in
ovenent II IS susceptible only TO
lakes elsewhere in the world than in
. islands Shocks here would hardly
traced on the tape. This is ac-
united for by Mr.. Nyswander as fol-
VS.: The Instrument is attuned to
arnors from other sections of the
orld Take two piano strings and
we each attuned TO the other. Twang
e and the other win sing. If they
g not attuned TO each other the