Da alene den sidste Methode tillader Anvendelsen af 
nøjagtigere Maaleapparater og derved i Regelen vil kunne 
give ulige større Nøjagtighed end den første, blev den ved- 
taget til Brug paa vor Expedition. 
Vindens Retning ombord observeredes efter Compasset. 
Dette, et Admiralitets Standard-Compas, stod paa Hytte- 
dækket, foran Rattet, ved c, Fig. 2. Staaende i Læ af 
Compasset, kunde man, med alle Vindretninger, der ikke 
gik over det agtenfor staaende Bestikhus h — hvilket ikke 
existerede 1 1876 — efter Følelsen af Vindens Virkning 
paa Ansigtet bestemme dens Retning og projicere samme 
paa Compasrosen med en Nøjagtighed, der svarer til om- 
trent en halv Streg eller 5 Grader. Ellers havde man til 
Vejledning og til Kontrol saavel Røgen af Skorstenen som 
Retningen af en paa Fortoppen hejst Vager, bvis Vinkel 
med Diametralplanet let lod sig bestemme og hvis Retning 
derigjennem kunde overføres til Compasset. Vageren, der 
brugtes i 1877 og 1878, var 1.4 Meter lang, se Fig. 1, 
og kunde saaledes observeres med Lethed fra Compasset 
af. I 1876 anvendtes ofte en liden Vimpel paa en Stage 
paa Forkant af Hyttedækket. 
Vindens Hastighed ombord observeredes med et Robin- 
sons Anemometer. lagttageren valgte en Plads paa Hytte- 
dækket, hvor Instrumentet var mest udsat for Vindens 
Virkning. I Regelen var dette paa Forkant af Hytten, 
men med Vinden agtenfor tvers stod han paa den luv Lodde- 
bro ( Fig. 2). 
som muligt, og med Omdrejningsaxen vertical. Registrerin- 
gen af dens Bevægelse varede i Regelen 30 Secunder. 
I 1876 brugtes en engelsk Vindmaaler, der i sin Tid 
var sendt fra Admiral Fitz Roy til den norske Fyrdirectør. 
Den havde 5 Skiver, hver inddelte paa Randen i 10 Dele. 
Skiverne drejede sig om horizontale Tapper, som vare stil- 
lede verticalt over hverandre. Armenes Længde, fra Om- 
drejningsaxens Centrum til Centrum af Halvkuglerne, var 
0.1538 Meter og Halvkuglernes Diameter var 0.1046 Meter. 
Ved Observation lod man i Regelen Instrumentet dreje sig 
frit rundt af Vinden, noterede, idet Uret viste 0 Secunder, 
Aflæsningen af Viseren paa det nederste Hjul, og derpaa 
Aflæsningen af samme, naar Uret viste 30 Secunder. Ved 
svage Vinde lod man ofte Registreringen vare 1, 1*/, eller 
2 Minuter.  Undertiden, naar Vinden var sterk, stillede 
Tagttageren, ved at dreje Korset rundt, Viseren paa neder- 
ste Hjul paa 0. I det Øjeblik, Registreringen begyndte, 
løftedes Instrumentet hurtigt op i Vejret, og naar de 30 
Secunder vare forløbne, førtes det hurtigt ned igjen og 
standsedes, hvorpaa Viserens Stand aflæstes. Undertiden 
brugtes et Timeglas i Stedet for Ur. 
De Observationer, som gjordes med dette Instrument, 
ere beregnede efter den tidligere antagne Regel, at Vindens 
Hastighed er 3 Gange saa stor som Halvkuglecentrernes 
Hastighed. Efterat det er bleven paavist, navnlig ved de 
Vindmaaleren holdtes i Haanden, saa højt. 
As the latter method only will admit of using appa- 
ratus for actual measurement, and as a rule, therefore, 
gives far superior results to the former, it was exclusively 
adopted on the Norwegian Expedition. 
The Wind's Direction on board was observed’ by the 
compass — an Admiralty standard compass, mounted (Fig. 
2 c) on the spar deck, immediately in front of the wheel. 
Standing to leeward of the compass, from whichever quar- 
ter the wind might blow, provided only it did not come 
straight aft over the deck-house h (put up in 1877), the ob- 
server could, by turning his face to the wind, tell the di- 
rection in which it was blowing, and project that direction 
on the compass-card with an accuracy corresponding to about 
half a point, or five degrees. ‘here was, too, the smoke 
from the funnel to act as a guide, and a vane at the fore- 
topmast head, the direction of which — the angle subtend- 
ing between it and the fore and aft line of the ship being 
easily determined — could be transferred to the compass. 
This vane — adopted in 1877 and 1878 — was 1.4 metre 
in length (see Fig. 1), and could therefore be easily observed 
from the compass. In 1876, a small pennant attached to 
the top of a pole on the fore part of the deck of the round- 
house, was frequently made use of. 
The Velocity of the Wind on board was measured with 
a Robinson's anemometer. The observer chose a position 
on the deck of the roundhouse in which the instrument 
would be most exposed to the wind. ‘This was generally on the 
fore part of the deck of the roundhouse; but with the wind abaft 
the beam, the observer stood on the windward sounding-bridge 
(1, Fig. 2). The anemometer was held in the hand, as high 
as possible, with its axis in a vertical position. The re- 
gistering of its motion lasted as a rule 30 seconds. 
The anemometer used on the first cruise, in 1876, 
was an English instrument, sent many years ago by Admi- 
ral Fitz Roy to the Director of Norwegian Lighthouses. 
It had five dials, each divided on the limb into ten equal 
parts. The dials revolved on horizontal pivots, arranged 
vertically one above the other. The length of the arms 
from the centre of revolution to the centres of the cups 
was 0.1538 metre, and the diameter of the cups 0.1046 
metre. When taking an observation, the instrument was 
as a rule allowed to revolve freely with the wind, the in- 
dication of the hand of the lowest dial being first read off 
at O seconds of the observer's watch, and then exactly 30 
seconds after. In a gentle breeze the registermg was 
frequently protracted for the space of 17/, or 2 minutes. 
Sometimes, when it was blowing hard, the observer would, 
by turning round the cross, adjust the hand of the lowest 
dial to zero. On commencing the registering, the instrument 
was lifted quickly up, and, at the expiration of 30 seconds, 
brought quickly down and stopped, after which the indica- 
tion of the hand was read off. Now and then an hour- 
elass was substituted for a watch. 
The observations taken with this anemometer have 
been computed on the assumption that the velocity of the 
wind was three times that of the cup centres. Meanwhile, 
this assumption is not admissible, as appears from the in- 
1* 
