44 
Slyngethermometret var inddelt i hele Grader. y er 
Vindens Vinkel med Kursen. Nogen bestemt Afhængighed 
af Forskjellen mellem begge Thermometre og Vinkelen y 
kan ikke sees. I Gjennemsnit vise begge den samme Tem- 
peratur. Middeltallet af Afvigelserne mellem begge, uden 
Hensyn til Fortegn, er + 0.°21. Dette Tal er ikke større, 
end at det nok kan forklares af Observationsfejl, Correc- 
tionsfejl og virkelig Forskjel mellem Temperaturen i Ther- 
mometerhuset og over Hyttedækket. Forsøgene med Slynge- 
thermometret modsige saaledes ikke den Antagelse, at Ther- 
mometret til Lufttemperaturen var anbragt paa en hensigts- 
svarende Maade og paa en heldig Plads. 
For muligens at kunne controllere Psychrometerobser- 
vationerne medtog jeg et Daniell’s Hygrometer, forfærdiget 
af Aderman i Stockholm. Dets Thermometre verificeredes 
af mig i Christiania. Det opstilledes, naar der gjordes 
Forsøg med det, paa Forkant af Hytten til Luvart. En 
Assistent aflæste paa givet Signal det indre Thermometer, 
medens jeg iagttog Duggens Tilsynekomst og Forsvinden. 
Begge stode vi 1 Le af Instrumentet. Observationen af 
dette Instrument var ingenlunde let. Der skulde for hver 
Gang flere Forsøg til, førend jeg fandt den rette Mængde 
Æther, der gay et tydeligt Belæg af Dug, som kort efter 
forsvandt. Naar denne Mængde var funden, toges en Række 
Forsøg, af hvilke de nedenstaaende ere Middel. Jeg vil 
efter dette ikke tillægge disse Forsøg, ligesom heller ikke 
de ovenstaaende med Slyngethermometret, synderlig Vægt. 
Resultaterne af Forsøgene vare følgende: 
The sling thermometer was graduated in whole de- 
grees: y is the angle subtending between the direction of 
the wind and the ship’s head. Any appreciable depen- 
dence of the difference between the two thermometers and 
the angle y cannot be detected. On an average, both were 
found to indicate the same temperature. The mean of the 
deviations between both, without regard to sign, is + 0.021, 
These figures are not greater than errors of observation, 
errors of correction, and the true difference in temperature 
within the thermometer-case and above the roof of the 
roundhouse, are amply sufficient to account for. Hence, 
the experiments with the sling thermometer do not oppose 
the supposition, that the thermometer for ascertaining the 
temperature of the air was mounted in a suitable manner 
and in a favourable place. 
With the object of possibly controlling the psychro- 
meter-obseryations, I took with me a Daniell’s hygrometer, 
made by Aderman of Stockholm. The thermometers of 
this instrument I verified myself in Christiania. It was 
mounted, when experiments were to be taken, on the fore 
part of the roundhouse, to windward. An assistant read 
off at a given signal the inner thermometer, whilst I ob- 
served the formation and disappearance of the dew. Both 
of us stood on the lee side of the instrument. To observe 
with this instrument was no easy matter. On each occa- 
sion several experiments had to be made before I could 
find the quantity of ether that gave a perceptible coating 
of dew, which shortly after disappeared. Having found the 
said quantity, I made a series of experiments, of which 
those tabulated below are the mean results. To these ex- 
periments, as also to those with the sling thermometer, I 
will not attach any great value. The results were as fol- 
lows: — 
Psychrometer, Daniell’s Hygrom. Vindhastiohed! 
Dag. ae =3 == ps, observeret. 
(Day.) Tørt. Vaadt. Dugpunkt. i B (Velocity of 
(Dry) (Fet.) ep (ian Roi) | én Wind observed.) 
1876. Juni 22. 10% 45" am. 13:05 T2206 Ong BL 12.015 HON ONE + 0.37” 7" pr. Sec. 
(June) ,. 7 O pm 14.0 13.0 I I.2 Bo & I I.5 + 0.3 6 
g 30 o 15 pm. Ro G ilo 2 9.0 0.5 8.9 — 0. I 7 
Juli. 2 7 © pm Do © 10. 8 8.9 10. 5 9.5 + 0.6 |.14 
(July) 8. 10 30 am. Ho Al 10. 6 Q.1 9.0 8.6  — 0.5 5 
så Å i 30 Pia, Hi Lo © kes i 9.4 09.4 8.8 | —©0 I 
Se Te OM ADIN 10. 6 8.4 6.8 7.0 7.5 0.7 7 
g 20 © AS jor. 10. 25 0: 35 8.2 8.5 8.3 + 0.1 3 
77 Aw TA © © jira, 10. 9 10. I 8.7 10.0 9.2 + 0.5 7 
Middel (Mean), Oo? Gate Agree 69% 
e, er Vanddampenes Tryk beregnet efter Psychrometret 
(Jelinek’s Tabeller), e, Vanddampenes Tryk beregnet efter 
Dugpunktet. 
| 
| 
e, is the force of vapour computed from the psychrometer 
(Jelinek's Tables); e; the force of vapour computed from 
the dew-point. 
