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



It is apparent that the albedo of III is really somewhat smaller than that 

 of I and II. For IV the difference is very considerable; the above values of 

 x point in the same direction, but by reason of the paucity of the observa- 

 tions they are too uncertain to permit any comparison with Pickering's results. 



The solution of the equations for I, II and HI on the supposition named 

 above gave the results : 



For I, II, m D : x = O."178 O."038 

 - I, II, III R : x = 0."263 O."034 



For combination with the already calculated values of the velocity k 

 they were again converted into parts of the Satellite's radius as follows : 



D R 



I. 0.340 0.501 



II. 0.408 0.601 



HI. 0.234 0.345 



For Sat. IV the values of x must be retained as they stand. They are 

 not of much importance for the present purpose. 



The next step was to apply the values of x to the observations of 1893 

 96 in order to reduce them to the aperture of the ^raw-telescope by means 

 of equation (7) and to compare the reduced times with the predictions of the 



Nautical Almanac. The results are contained in Table b where A' is the 



(7 4\ 2 

 -jp\ 1, T' NA is the diffe- 

 A 1 



rence between the observed and the predicted time, T T' the reduction as 

 calculated by equation (7), and T NA the correction which must be applied 

 on the times of the Nautical Almanac in order to make them applicable to 

 the From, instrument. The list contains all the published observations exclu- 

 ding only those in the years 1893 and 1896 which fall quite outside the arctic 

 observations of the phenomenon in question. The remarks which in many 

 cases are added to the original observations, were omitted; only a: after 

 the number indicates some source of uncertainty as haze, bad images, twi- 



