Appendix B. 



Hence the same Prof, ilillosevich advised us to assume with full confidence 

 the corrections for the lunar co-ordinates received from Grei'invich, and these 

 yielded the longitude for Bujongolo : 



\ = 2" 0"' G"-3 E.G. 



This again agrees closely with the value 2'' 0" G^'O East Greenwich, 

 obtained liy Prof. Millosevich, who was also good enough to make the same 

 calculation. 



The latitude was obt;iined from two meridian altitudes and from two series 

 of circummeridians (Obs. Nos. 38, 43, 44, 46, and 49 to 54), observed partly 

 by H.R.H. and partly by Commander Cagni. Between the results of the two 

 observers there occurs a considerable difference, the origin of which may 1)6 

 attributed to some anomaly of refraction. In fact, H.R.H. was in this instance 

 induced to depart from his practice of observing the lower liml> of the sun, 

 owing to an unusual optic phenomenon which caused him to notice on the lower 

 edge of the reflected image a false liml) which would not have allowed a good 

 observation. Hence the discrepancy in the results is to be attriliuted to this 

 particular state of the atmosphere. Therefore, in order to prevent the 

 observations of H.R.H., which were the more numerous, from too greatly 

 influencing the results, the mean of the circummeridian series was first 

 obtained, and the resulting value taken as a mean with the results of the 

 meridian observations. The se^'eral values thus obtained are : 



17th June. — Meridian — Commander Cagni = 0' 19' 50" N. 



9th July. — „ —H.R.H. „ = 20 55 „ 



10th ,, — Circummerid. — Commander Cagni ,,= 19 52 ,, 



Uth „ —Meridian — H.K.H. „ = 20 54 „ 



These data yielded for 



Bujongolo = 0= 20' 23" X. 



With the longitude of Bujongolo is obtained the alisobite correction of 

 the chronometer for the period of arrival at that encampment, and subsequently 

 the mean daily correction of the same chronometer for the period occupied by 

 the journey. 



Thus was oI)tained : 



Bujongolo.— 19th June, 3" 4.5" ... C,„= + 5" 1.5"' 37=-l 



... X =+-2 6-3 

 Ki=-f3 15 30-8 



This absolute correction on mean Greenwich time corresponds with the 

 date of 11th June at 3'' 45'" of mean local time. And as at Entebbe on 

 11th May, at 23" 31" of mean local time, we had K, = 3" 16" 34^- 9, we shall 



314 



