( ioi ) 



North stars South stars 



180 c 



210 



240 



270 



300 



330 



— 5° 12' 



2"72 

 5.30 

 5.23 

 6.65 



1.25 

 4.89 



2" 57 

 5.59 

 5.51 

 5.63 

 2.43 

 4.29 



This result may be combined with that of 1900 — 01. For the 

 latter I adopt the first value of Contrib. I p. (284), but I estimate 

 its mean error to be not less than that which I have now found. 

 Thus : 



Latitude of the pier of observation. 

 1900-01 — 5° 12' 4".01 ± 0".6 

 1903 4 .34 db .6 



Together — 5°12'4"2 ± 0.4 

 I think that the agreement is quite satisfactory. 



IV. Determinations of the longitude and the latitude of N'Kuiu, 

 Mayili, Buku-Zan and Chimbete. 



1. Journey of 1903 December 22 — 31. Observations at N'Kutu. 



During this journey the chronometers were transported all the way 

 by water, hence extraordinary perturbations are not to be feared. 

 But the temperature was certainly higher than at the same time at 

 Chiloango ; it amounted at least to 26° and may have been between 

 26° and 30\ A comparison of the rate of Hewitt from Dec. 20 

 to Jan. 3 with the mean reduced rate for those months would yield 

 a temperature of 26°. 4, which is of course an uncertain estimation. 

 Although there is no reason to expect any difference in temperature 

 between the journey to N'Kutu and the journey back, yet the uncer- 

 tainty about this affords a disadvantage for Hewitt and therefore, 

 for the determination of the longitude, I have finally given equal 

 weights to the two chronometers. 



The computation of the time and the latitude at a place of which 

 the geographical position is unknown had of course to be made in 

 successive approximations. Here I shall give only the final results. 



