Da en Sammenligning den 12te Juni mellem den nye 
Vindmaaler og den ældre gav den første en Frictionscoeffi- 
cient af 1.4, har jeg for 1877 regnet med Coefficienten 
AL 16: 
1878. 
Log. Vindmaaler. 
Datum. Kyartmil | Meter Meter | Frictions- 
1 Timen. | pr. Secund. | pr. Secund. | Coefficient. 
Juni 18 Folk Bey 2.55 | + 1.15 
Juli 5 6.7 | 3-5 Dog | 182 
TO 3.6 2.4 1.2 
20 7.0 | 3.6 2.4 ho 
3 G 7.0 | 3.6 2.35 1.25 
Aug. 30 6.5 | 3.4 2.45 0.95 
Middel + 1.16 
For 1878 har jeg antaget Coefficienten til + 1.2. 
Dersom man for Registreringen stillede Viseren paa 
det Tal, der angiver Frictionscoefficienten, vilde man efter 
30 Secunders Registrering kunne aflæse directe Vindens 
Hastighed 1 Meter pr. Secund. Paa vor Expedition stille- 
des altid Viseren paa 0, da det paa Forhaand ikke kunde 
garanteres, at Frictionscoefficienten holdt sig constant. 
Skibets Kurs observeredes efter det samme Oompas 
som Vindens Retning og noteredes paa hele Grader. Com- 
passets Deviation var altid nøje kjendt, efter de lagttagelser 
og Beregninger, som vare udførte af Captein Wille. Skibet 
svingedes for Deviation i 1876 i Husø, ved Sognefjordens 
Munding, 1 1877 i Husø før Rejsens Begyndelse og 1 Vest- 
fjorden ved dens Slutning, i 1878 i Bergen, udenfor Vardø, 
udenfor Hammerfest, ved Beeren Hiland, i Grøplandshavet, 
ved Spidsbergens Sydkap og under Grønlandsisen Vest for 
Spidsbergen. 
Da Deviationens Størrelse var merkelig afhængig af 
den geografiske Position i de Farvande, som Expeditionen 
besøgte i 1878, var det nødvendigt ved Beregningen af 
Af 
Vindens og Skibets Retning at tage Hensyn hertil. 
Capt. Wille modtog jeg til dette Øjemed to af ham udar- 
bejdede grafiske Fremstillinger, nemlig J° et Kart over den 
i 1878 gjennemsejlede Del af Havet, paa hvilket var op; 
trukket Linier for ligestore Verdier af den i Formelen for 
Compassets Deviation benævnte Coefficient B, der omtrent- 
lig angiver Deviationens Maximumsværdi, og 2" en Række 
Deviationscurver (Argument: anlagt Kurs efter Compasset, 
Function: Deviationens Størrelse i Grader) betegnede med 
forskjellige Farver og ordnede paa samme Plade med 
fælles Kursargument samt optrukne for forskjellige be- 
stemte Verdier af Coefficienten B. For paa- 
værende Plads kunde saaledes af Kartet No. I udtages 
Værdien af B og med denne samt anlagt Kurs pr. Com- 
pas kunde af No. 2 udtages den tilsvarende Verdi af 
enhver 
10 
Å comparison, on the 12th of June. between the new 
and the old anemometers, having indicated according to 
the latter, a friction-coefficient of 1.4, I computed for 1877 
with the friction-coefficient —- 1.6. 
1878. 
Log. Anemometer. 
Date. Naut. Miles | Metres Metres | Friction- 
an Hour. | per Second. | per Secon | Coefficient. 
June 18 Fol Fo] 288 | 4b ang 
July 6.7 3-5 208 182 
5 55 7.0 3.6 2.4 Ho 
na 20 75) 3.6 2.4 oD 
5 3 7.0 3.6 2.35 1.25 
Aug. 30 6.5 3.4 | 2.45 | 0.95 
Mean. + 1.16 
For 1878, I adopted the coefficient + 1.2. 
If, before registration, the index were adjusted to the 
cipher indicating the friction-coefficient, the observer, after 
registering 30 seconds, could read off at once the velocity 
of the wind in metres per second. On our Expedition, 
however, the index was always adjusted to zero, since be- 
forehand it is impossible to tell with certainty whether the 
friction-coefficient will remain unchanged. 
The Ship's Course was observed by the same compass 
as the direction of the wind, and noted in whole degrees. 
The deviation of the compass was at all times accurately 
known, from.Captain Wille’s observations and computations. 
In 1876, the ship was swung for deviation at Husø, at the 
mouth of the Sognefjord; in 1877, at Husø, before the 
commencement of the cruise, and im the Vestfjord at its 
termination; in 1878, at Bergen; off Vardo; off Hammer- 
fest; at Beeren Hiland; in the Greenland Sea; off Cape 
South, Spitzbergen; and at the Greenland ice barrier, west 
of Spitzbergen. 
The amount of deviation being perceptibly dependent 
on the geographical position of the vessel in the tracts of 
ocean visited by the Expedition in 1878, it was necessary 
when computing the direction of the wind and of the ship, to 
take this circumstance into account. Captain Wille pro- 
vided me with two diagrammatic representations, which he 
had specially prepared for that purpose. viz. 1, a chart of 
the tract of ocean explored by the Expedition in 1878, on 
which were lines indicating equal values of the coefficient B 
in the formula for the deviation of the compass, which coeffi- 
cient approximates the maximum value of the deviation; and 
2, a series of deviation-curves (abscissae: course by compass ; 
ordinates: deviation expressed in degrees) marked with 
different colours and arranged on the same Plate, according 
to common course-abscisse, for different definite values of 
the coefficient B. Hence, for each position of the ship, 
the value of B could be found on chart I, and, with 
this value and the course by compass, the corresponding 
