I. — Astronomic ()bserv\ations. 



Here Nos. 2 and 3 point to irregularities in their movement. For this reason, 

 and also Ijecause the daily comparisons were occasionally omitted, it was 

 considered desirable to make use only of the indications of the No. 1 

 chronometer, which was in fact the one generally employed for the observations. 

 With the -snew of fi.xing, if only approximately, the daily correction of the 

 Xo. 1 chronometer for the period of the journey, the calculation of the 

 astronomic elements of Bujongolo was taken in hand, and here were recorded 

 determinations of time between 11th and 2sth June, taking the latitude at 

 (p = 0' 20' 16" X., roughly obtained from the already determined elements. 

 The corrections of the No. 1 chronometer on the mean local time were for 

 Bujongolo : 



„ - + 29-4 



From the mean of the results for 11th and 2Sth June respectively, we 

 get, omitting the intermediate observations : 



11th June, 3" 45"" C,„. = +5'' 1.5'" 37^-1 



28th „ 20 25 „ = + 5 15 28 -1 



Interval H""'-' 16" 40"' Difference 9^0 



Hence : B = - 0=-509. 

 The change occurring in the mean daily correction of this chronometer is 

 seen to be considerable, if the value just found be compared with that previously 

 obtained at P^ntebbe ( - 2^'762). But now we merely require an appro.ximate 

 value of the longitude of Bujongolo foi' the calculation of the emersion of 

 B A C 81, and this will give us the absolute longitude of that same point. 

 Hence we take the by no means arbitrary course of adopting, as mean daily 

 correction of the No. 1 chronometer during the journey, the mean of the two 

 daily corrections obtained at Entebbe and at Bujongolo, that is to sav : 

 B, = - ^'■^^■' + 0"^Q9 ^ ^..g3_ 



* The date is astronomic, and the hour is referred to the mein local time . 



311 



