114 



GEELMUYDEN. ASTRONOMICAL OBSERVATIONS. [NORW. POL. EXP. 



from 9 p.m. For the following observations, taken about 6 in the afternoon of April 2, was 

 assumed ? = 86 0'. Ind. corr. (0'?). 



To the second observation with the glass horizon has been applied the correction + 30' 

 (the limb being divided to half degrees). These three observations were very difficult. 



Supposing that the altitudes measured from the apparent horizon require a correction 4h, 

 owing to irregular terrestrial refraction, and that the assumed latitude is erroneous by the 

 amount 4<p, the two sets of observations give the equation 



5h 56m 39 _ o.OH Jy = & 5 53s + 0.143 J<p - 0.966 Jh, or 0.966 Jh - 0.154^ = 9.85, 



and supposing further that the meridian altitude of the next day, taken under the same meteoro- 

 logical conditions, requires the same correction, which gives 4<p = 4h, the result will be : 



1.12 Jh = 9'.85 or 4h = + 8'.8 and Jy = - 8'.8, 

 and LT-I = 5^ 56m &>. Combining this with I-Gr. = Oh 52m 52s, gi ve n on p. 112, the result is 



April 2, 6 p.m., E. Long. = 6^ 49m 0" = 102 15' 

 and April 3, Noon, N. Lat. = 85 55'. 



1895, April 4, Bar. 30.58 in., Therm. - 31.3 C. 



After leaving the camp of the preceding day at 3 o'clock in the morning the following 

 observations were taken on the way, about four hours after starting. Assumed Lai 86 5'. 

 Height of eye 16 feet, Ind. corr. 0. 



If the altitudes require the correction dh, and the latitude the correction dtp, the mean of 

 the five altitudes will give: 



Watch I lh 50m, LT-I = 5^ 47m 33* + 0.416 ^> + 1.063 4h. 



A comparison of this number with those of April 2 gives a strong corroboration of the 

 assumption there made. The meteorological conditions being nearly the same, the same value 

 of 4h may be employed. As to y, the value assumed above would correspond to an advance 



