Full resolution (JPEG) - On this page / på denna sida - Sidor ...
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
16
Glasroret, af hvilket saaledes deu atmosfæriske Luft blev
udjaget. Naar Instrumentet kom ombord, endevendtes det.
saaledes at Kranen h kom ned og Glasrøret op. Man
bevægede nu Yandhenteren lidt frem og tilbage med den
øvre Ende. og hvis der havde været Overskud af Luft.
maatte denne have arbejdet sig op. og vist sig i Toppen
af Glasrøret. Dette viste sig
imidlertid i ethvert Tilfælde fuldt af
Vand lige til Tops. og blev derfor
i den senere Tid ikke paasat.
Til mindre Dybder, og naar
man ikke behøvede at standse
LTdfi-ringen, benyttedes en mindre
Vand-henter konstrueret af Professor
Ekman i Stockholm. Dette Apparat
er fremstillet i Fig. 12. Det
bestaar af en i begge Ender aaben
Cylinder c, der har en Brem rundt
om den øvre Kant. Denne Cylinder
løber op og ned langs tre1
Styrestænger cl. hvis øvre Ender er
forbundne meel et Tværstykke, og de
nedre Ender er fæstede til en
Buncl. der ’har en med Fedt eller
Guttapercha fyldt Udskjølpning
rundt om, i hvilken Cylinderens
nedre Kant passer. I denne Bund
er ogsaa en Udtapningskran. Fra
Midten af Bunden staar op en
Stang, der bærer en Skive med
Kanter af ombøjet Kautschuk, og
som lukker Cylinderen foroven,
naar den er sluppet ned. I denne
Skive er et Svikhul, lukket med
en Prop. Cylinderen hukes med
en Sliphage a i det øvre
Tvær-stykke mellem Stængerne, og denne
Hage holder da Cylinderen oppe,
medens Apparatet løftes over og
langs Skibssiden, men naar man
lader det falde i Vandet, løftes
Cylinderen lidt af Vandtrykket
under Bremmen og Sliphageu
falder ned. Vandtrykket holder da
Cylinderen fremdeles oppe,
saalænge Instrumentet synker raskt,
men idet man standser Udfiringen
eller ved Bunden, falder den ned og indeslutter Vandet.
Hag en b griber tat under Bundstykket og hindrer
Cylinderen fra at løfte sig mere, naar den engang er faldt ned.
1 I Figuren er for Tydeligheds Skyld kun tegnet to.
the spiral copper tube, it also flowed into the glass tube,
expelling the atmospheric air. So soon as the instrument
came on board, it was inverted, the stopcock (h) pointing
clown and the glass tube up. The upper end of the
apparatus being then moved gently backwards and forwards,
the surplus of air, had any such existed, must obviously
have forced its way upwards, and
have appeared, in the form of
bubbles, at the top of the giass
tube, which, however, was
invariably found to be full of water;
and hence we ceased to attach it
when the fact would no longer
admit of doubt.
For moderate depths, and when
not obliged to check the line in
veering out. we used a smaller
water-bottle, constructed by
Professor Ekman of Stockholm. This
instrument is represented in Fig.
12. It consists of a brass cylinder
(c), open at both ends, and with
a flange round the upper rim.
The cylinder slides up and down
31 metal guides, the upper ends of
which are connected by a beam,
the lower end being fixed to a
circular .bottom-piece, having a
grooved rim filled with grease or
guttapercha, into which the
cylinder fits. The bottom-piece is also
provided with a stopcock; and.
projecting upwards from the centre,
extends a stout rod, bearing a
metal disk, the rim of india-rubber,
which serves to close the top
end of the cylinder, on the latter
having slid down the guides. In
the disk is a spigot-hole, stopped
with a plug. The cylinder is
attached to the beam, between the
guides, by means of a slipping-hook
(a), which keeps it suspended when
lifting the apparatus and lowering
it over the ship’s side; but on its
reaching the water," the pressure
against the under surface of the
flange slightly raises the cylinder
and slips it ofl" the hook.
Meanwhile. the pressure of the water
will retain the cylinder at the top
of the instrument, the descent being sufficiently rapid; but
on checking the line, or the instant the machine touches
the bottom, it will slide down and shut in a sample of
1 To avoid apparent complexity, only two of the guides are shown
in the figure.
Fig. 12.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
