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13
Heldning, og .endelig selve Keglens Heldning paa 42°.
Paa Østsiden sees Underdelens Skraaning paa 10° at skyde
sig foran de fjernere, i Skygge liggende Partier, der staa
ucl som Ribber fra den geometriske øvre Kegle. Solen
stod, da Kraterets Konturer og Skygger skitseredes, i Vest,
i Papirets Plan.
Den stejle Kratervæg er paa mange Steder snefri, og
den sorte Aske viser lier store Flekker af ofte bizarre
Figurer. Kraterranden er tagget, men Sneen, der dækker
den, giver Randen med dens Tagger ejendommelig bløde
Omrids. Krgterranden er højest paa Vestsiden; der
maal-tes en gjennemsnitlig Heldning af den øverste Linie af 2l/2
Grad. Det højeste Punkt af Beerenberg ligger saaledes
(nu) paa Kraterets Vestside og, som Fig. 4 viser, noget
mod Nord.’ Det er dette Punkt, hvis Højde vi have søgt
at bestemme med et rundt Tal til 1950 Meter.
Fra Loddestationerne toge Officererne Pejlinger til
Øens nordlige og sydlige Del. At bestemme Skibets
paa-værende Plads efter Pejlingerne og Scoresby’s Kart, viste
sig omtrent ugjørligt, da dette, i Overensstemmelse med de
ældre hollandske Karter, giver Sydlandet for langt og for
smalt.
Medens vi vare paa Søen, havde vi Anledning til at
iagttage de voldsomme Hvirvelvinde, der kunne blæse under
Beerenberg. For et Sejlskib maatte disse være vderst
generende med ele pludselige Omslag i Vindens Retning
under sterke Byger. I disse maaltes en Vindhastighed af
15 Meter pr. Secund. den største Vindhastighed vi iagttog
under 1877 Aars Rejse. Fra Søen saa vi, hvorledes det
fine Tufsand fra Ægøen reves løs og førtes højt op i
Luften som en mørk Røgsky meel de sterke Vindbyger. Med
den vulkanske 0 for Øjne skulde der ikke nogen sterk
Indbildningskraft til, for at man kunde tro at se Ildsluer
bryde ud fra Ægøen og saaledes komme til at medbringe
Efterretning om at have været tilstede ved et vulkansk
Udbrud. Heldigvis havde vi Dagen før havt Anledning til
at overbevise os om Sagens sande Natur. Om Aftenen
ankrede vi i den store Rækvedbugt et Par Kvartmil i
Sydvest for den forrige Ankerplads.
Næste Morgen, den 2den August, var Beerenberg
fremdeles synlig. Vi lettede og stod østover, passerede
Ægøen og loddede i 195 Favne udenfor Sydbræen. Paa
Veien saa jeg tydelig inde paa Underlandet under Krater
Vogt det af Carl Vogt i 1860 observerede og beskrevne
låve Krater Berna. Fremdeles saa jeg, at Sydbræen gik
lige til Stranden, men at dens nederste Del var bedækket
med Smuds. Efter Lodningen gjorde vi et Forsøg til
Bestemmelse af Højden af Beerenberg. Efter et godt Med
(Ægøens Kant over et markeret Punkt inde paa Land)
sejledes i en nøjagtig udmaalt Tid, medens Skibets Fart
hvert 5te Minut observeredes efter Loggemaskinen. Ved
Begyndelsen og Enden af dette Tidsrum maalte med Sex-
short distance 280-, the incline of the upper cone itself
reaching, as previously stated, 42". On the east side, the
slope of the lower cone, that shelves at an angle of 10°,
was seen extending before the more remote parts of. the
upper declivity, which lay in shadow, and like huge ribs
project from the upper cone. When sketching the contours
and shadows of the crater, I had the sun in the same
plane as the paper.
The precipitous walls of the crater being in many
places bare of snow, large patches t of the black
surface make their appearance, many of them grotesque in
form. The ridge of the crater is extremely rugged: but
the snow covering the jagged edges imparts a wonderful
softness of outline. The ridge of the crater is highest on
the west side; and its average incline was found to be 2:i/2
degrees. The most elevated point of Mount Beerenberg is
accordingly (now) on the west side of "the crater, and, as
shown in Fig. 4, lies a little towards the north. It is this
point the altitude of which we have approximately
determined at 6400 feet.
From the sounding-stations, the ship’s officers took
bearings of points in the northern and southern parts of the
island. To determine the ship’s position from bearings and
Scoresby’s map proved well-nigh impossible, since the latter,
based as it is on the earlier Dutch maps, gives the
southern part of the island at once too long and too narrow.
Whilst engaged in sounding, we had opportunity of
observing the violent whirlwinds that are often encountered
on passing east of Beerenberg. To sailing-vessels they
must prove a serious annoyance, owing to the sudden
changes in the direction of the wind during heavy squalls.
On one such occasion the velocity of the wind was found
to reach 15 metres a second, the greatest velocity observed
on the cruise in 1877. In the strong eddying gusts the
. fine tuff-sand of Egg Island would be caught and whirled
aloft like a dense cloud of dust or ashes. With the
volcanic island in immediate proximity, it required no great
stretch of the imagination to fancy you saw flames bursting
forth from the crater, and thus bring away the erroneous
impression of having witnessed a volcanic eruption.
Fortunately, we had had on the previous day opportunity of
ascertaining the true nature of the phenomenon. In the
evening we cast anchor in Great Wood Bay, a couple of
miles south-west of our former anchorage.
Next morning, August the 2nd. Mount Beerenberg
was still visible. We got under weigh, steering east, past
Egg Island, and sounded in 195 fathoms, off the southern
glacier. As we steamed along the coast. I could plainly
distinguish on the low-lying tract beneath Vogt’s crater
the low Berna crater, observed and described by Carl Vogt
in 1860. Moreover, I coidd follow the direction of the
southern glacier to where it reaches the sea: its lower
extremity was covered with dirt. After sounding, an attempt
was made to determine the altitude of Mount Beerenberg.
Selecting a good bearing (the base of the outer wall of Egg
Island in a line with a salient inland point) we steamed ahead
in this direction for a given time, accurately measured, the
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