Survey of Northeast Greenland. 141 
7 — 
|] g 
| re : App. | Refrac- | inafı 
Star Telesc. Temp. | Barometer Er ae | Secale wih 
| ke il 5 
| SANS а i | 76°46’ 
a Geminorum.. | Е -+ 94| 761.6(+ 15.5) |71°05'23”.2| 3'00”.8 | 08".9 | 
a Geminorum.. | W | -+14.2| 748.1 (+ 16.0) | 71 0522.7 | 301.2 | 09.2 | 
д Aquilæ ...... w + 94| 761.6(+ 15.5) |73 4647.6 | 3321 | | 177.9 
0 Aquilæ ...... Е |-+142| 748.1 (+ 16.0) | 73 4635.0 | 3323 | 05.2 
2 Geminorum.. W |+ 9.4! 761.6(+ 15.5) | 74 5507.8 | 348.6 | 06.5 
В Geminorum.. Е |— 142 748.1 (+ 16.0) | 74 55 07.8 348.7 | 06.5 
д Leonis....... | w |+ 2.3! 753.5(4 17.1) |82 04531 | 650.8 | 16.4 
Pokeonis:....... | Е |- 52| 760.7(+ 17.0) |82 0445.4 | 659.9 | 15.6 
PALES... 2... I We | = 2.5 | 753.5 (+ 17.1) | 82 47 25.1 728.0 | 247 
ge Aquarii. - | М |-- 2.1! 753.1(+ 15.9) | 86 3912.0 | 1352 | 10.2 
shown by the terms of accuracy — but the mean errors show at 
the same time that the result must rather be supposed to have lost 
in reliability by being computed from all the thirty-nine stars; in 
other words, the opposite of what one would be justified in expec- 
ting, unless one of the sources of the error — the uncertainty 
of the refraction — played a much greater part as regards the 
twenty-one last-mentioned stars than as regards the eighteen first- 
mentioned ones. 
The difference between the two values of the latitude corre- 
sponding to the culmination north and south of the zenith shows 
that the values computed for the refraction have on an average been 
too great. Accordingly one was justified in expecting that this 
difference would increase proportionally to the refraction. However, 
this does not appear from the observations; the difference which 
arises between the culminations north and south of the zenith is 
practically speaking the same in the case of the eighteen stars with 
small zenith distances as in the case of the entire group of the 
thirty-nine stars. There is, however, nothing to be alarmed at in 
this state of affairs, which is principally due to the fact that the 
first sub-division with small zenith distances comprises far too few 
stars to enable one to get even a fairly reliable impression of the 
error of refraction, which is here bound to be very slight i. e. 
considerably smaller than the error arising from pointing the star. 
The idea least open to objection as regards the error of the computed 
refraction one forms by treating the entire group of thirty-nine stars 
together. The mean value of the refraction computed for all thirty- 
nine stars is 94”.0, whereas the difference between the two values 
of the latitude computed from southern and northern stars is 2”.93. 
