144 
Middelværdien af Æ under Forsoget er saaledes 
7.60239, istedetfor den oprindelige Verdi 7.62798 eller 
dH = —0.02554 og vi faa 
| 
—0.02554 
, 0.02554 
TH0—H IG T 
ip =f Dane ae 0.0104 f. 
Correctionen bliver 1.04 Procent af Fordunstningsmæne- 
den i Tidsenheden, og, da den hele Fordunstningsmængde, 
ceteris paribus, er proportional med denne, faa vi i vort 
Exempel en Correction af — 60 x 0.0104 = — 0.624 
cbem. Den hele Correction naar saaledes ikke op til en 
Kubikeentimeter, Grænsen for Nøjagtigheden tilsøs. I 
Strøg, hvor Fordunstningen er raskere, bør Fordunstnings- 
skaalen være rummeligere eller hellere Maalingerne gjøres 
hyppigere. 
I 1877 stode begge Fordunstningsmaalere ved Siden 
af hverandre. Deres Resultater kunde saaledes sammenlig- 
nes. Observationerne gjordes i Regelen Kl. 9 Form. og 
Kl. 9 Aften. Resultatet af de anstillede Sammenligninger 
var følgende: 
Hence, the mean value of Æ during the experiment to on 
was 7.60239, in place of the initial value, 7.62793, or dH = 
0.02554, and this gives 
—0.02554 _ 
å 4 . 0.02554 
WY = Ra = 
=i eS Oy. 
The correction is 1.04 per cent of the water evap- 
orated in the given unit of time, and. since the total 
amount evaporated, ceteris paribus, is proportionate to the 
latter, we have in the example a correction of 60 x 0.0104 
= — 0.624 cbem. The whole correction, therefore, does not 
amount to one cubic centimetre —, the limit attainable at 
sea. In localities where the evaporation is more rapid, 
the evaporating dish should have greater capacity. or the 
measurements be made at shorter intervals. 
In 1877, the two atmometers were mounted side by 
The results of the observations could thus be com- 
The observations were generally taken at 9 a.m. 
The result of the comparisons was as 
side. 
pared. 
and at 9 p.m. 
follows: — 
1877 Dag Time. Tidsrum. Fordunstnings-  Forskjel. 
højde. 
Height of Water 
Day. Hour. Interval. Evaporated. Difference. 
A B A—B 
Juni (June) 12 OS am= CO jo Wish gna goofy OPA 
— 2 Oy 25pm SSS 072 
= — mg=t4 =o © pin—= O 5 Sim, 13. 5 1.44 1.86 —0.42 
== — 14 10. 2 am.— 8.5 p.m 1, 8 00 220 0.80 
14—15 8. 75 P.m.— 8. 75 a.m. Oo O02 OKA 0.08 
= = 1g 0-0 am.— 8. 75 p.m io 75 120 LOU 0.19 
== —- 16-17. 97 a.m.— 09.4 PM. 11.75 0.09 0.01 0°08 
== —= HY=20 So 75 fDi — 1G, © Ei, (1430 BF 5005 Oo —0.40 
== oh 2/2 II. 3 am— 9.6 pm 1 3 go 2100 0.33 
— — 22—23 9.6 pm.— 9.5 am Wo © 287 128 IoD 
= — 23-24 9.5 aM— 5.5 PM. 32.0 3.15 3.690 —0.54 
= = 28 O | Sill —=u©, @ pin 12. 5 DoS BG =O3}0) 
Juli (July) 9 I1. 5 am— 7.5 p.m. 30 mg 097 0.00 
Sum: Dagtimer (Day Hours) . JG LAVA? FAAR RED 
* Nattetimer (Night Hours) 2.2 2i@Q NAN 0.12 
å Dag og Nat (Day and Night) 32.0 BEG 3:67 —0.52 
Ialt (Total) 
I det Hele taget give saaledes begge Fordunstnings- 
maalere meget nær samme Resultat. 
i den sidste Rubrik, uden Hensyn til Fortegn. er 4.76. 
Summen af Tallene 
170."00 DS FRT QO! +- 0.75" 
On the whole. both atmometers give accordingly very 
nearly the same result. The sum of the figures in the 
first column, without regard to sign, is 4.76, from which 
