104 
Formel (Formula): b, = 753.93 — 0.244 sin (8° 49.8 1 ¢) +0.””104 sin (83° 15’ + 26) 
++ 0.018 sin (98° 25’ + 36) + 0.7019 sin (128° 40’ I 40). 
Figuren Pl. I, Lufttryk 1878, viser, at den bereg- 
nede Curve stemmer meget godt overens med de observe- 
rede Verdier. MF = +0.""019. 
Efter Formelen beregnes: 
1 Maximum 907210) 
2 
Medium indtræffer: 1” 6” a.m. og 10” 23” a.m. 
Amplitude: 0.””538. 
Efter de observerede Værdier kunde muligens Morgen- 
Minimum lægges nærmere Kl. 7, f. Ex. 6” 45” am. og 
synke til —0.””34, samt Aften-Maximum lægges ved 9” 
50” p.m. og række + 0.””[6. 
Af Figurerne Pl. I ser man, at den af vore timevise 
Observationer resulterende daglige Periode for Lufttrykket 
er i det Store taget meget lig i de forskjellige Aar eller 
paa de forskjellige Bredder. Minimum optræder med Be- 
stemthed i Morgentimerne 3 til 6 og Maximum om Efter- 
middagen, en Periode, der minder mere om Lufttempera- 
turens daglige Periode end om den sædvanlige Periode for 
Lufttrykket paa Land-Stationer og i det tropiske Atlanter- 
hav. I 1876 og 1878 har Perioden 2 Slag, med et secundært 
Minimum om Eftermiddagen og et Maximum sent om Af- 
tenen, noget som ogsaa antydes i Curven for 1877, der har 
en liden Sænkning ved 5 p.m. 
Da de 3 Curver have saa stor Lighed, har jeg til et 
Forsøg beregnet følgende Mediums-Curve for de 3 Aar, idet 
hvert af disse er tillagt samme Vægt. 
81 25 pan 
3 + 0.77145, 10” 41" p.m. 
| The figure in Pl. I, Pressure of the Air, 1878, shows 
that the computed curve agrees very well with the observed 
values. MF =+ 0.019. 
From this formula are computed — 
— 0Q.nm328, 5% 48" a.m. 
= 0.2099, gn 3 
3” p.m. 
1 Minimum 
2 
The Mean occurs 1” 6” am. and 10% 23” a.m. 
| Total Range: 0.””538. 
| According to the observed values, the morning mini- 
| mum might possibly be placed somewhat nearer 7 o'clock, 
for example 6” 45” a.m., and sink to —0.””34, and the 
evening maximum be put at 9” 50” p.m. and reach to 
IE OAS, 
From the figures in Pl. I, it will be seen that the - 
diurnal period of pressure resulting from the hourly obser- 
vations, is on the whole much the same in the different 
years or in the different latitudes. The minimum occurs 
| invariably in the early morning hours from 3 to 6, and 
the maximum in the afternoon, a period having more in 
common with the diurnal period of the temperature of the 
air than with the usual period for pressure at land-stations 
and in the tropical parts of the Atlantic. For 1876 and 
1878 the period has 2 waves, with a secondary minimum 
in the afternoon and a maximum late in the evening, which. 
indeed, is also indicated by the curve for 1877, that exhibits 
a slight depression at 5 p.m. 
| The 3 curves resembling one another so closely, I have 
computed the following mean curve for the 3 years. the 
same weight being attached to each. 
a.m. 
Klokkeslet 1/ JE 3? 4" gå 6” gå 8! 9” noe nee gal Hour. 
Middelafobs. Verdier —o.07 —o.18 --0.24 —0.30 —0.26 —0:21 —0.20 —0.09 —0.08 0.00 0.06 0.16 Mean of obs. values. 
af beregnede , —o0.08 —0.17 —0.26 —0.29 —0.27 —0.22 —0.16 —0.12 —0.07 —0.01 0.07 0.15 ,, of computed do. 
Forskjel: Obs. — Ber. 0.01 —0.01 0.02 —0.01 0.01 0.01 —0.04 0.03 —0.01 0.01 —0.01 0.01 Diff.: obs. — comp. 
p.m. 
Middelafobs. Verdier 0.23 0.25 0.20 0.21 0.16 0.13 0.07 0.08 0.04 0.07 0.05 0.00 Mean of obs. values. 
» af beregnede ,, 0.21 0.24 0.22 0.20 0.16 0.12 0.08 0.06 0.05 0.06 0.05 0.00 , of computed do. 
Forskjel: Obs. — Ber. 0.01 0.01 —0.02 0.01 0.00 0.01 —0.01 0.02 —0.01 0.01 0.00 0.00 Diff.: obs. — comp. 
Middel af Forskjel. 
+ 0.012, 
Værdierne ere afsatte i Figuren, Lufttryk 1876— 
(Ue, WG I 
uden Hensyn til Fortegn 
The mean of the difference. without regard to sign, 
| = dp MAAN, 
| a : : 
| The values are set down in the figure. Pressure of 
| we Avie, ISCG—77—= 73, IPl, 16 
