I. — Astronomic Observations. 



The expedition of H.K.H. was supplied with four pocket chronometers at 

 mean time, and before starting on the journey these were kept under contml 

 at the Hvdrographic Institute. During this period of control, the ahsolute and 

 daily corrections recorded for the said chronometers at C of mean Greenwich 

 time yielded the following results : — 



After leaving Genoa, and more particularly during the voyage by steamer 

 from Naples to Port Said, the chronometers were left unregulated. But at 

 Port Said they were again set going, and on 20th April, 1906, compared with 

 the chronometer at the Police Station, in order to record their absolute 

 correction. 



On the 26th of the same month another comparison was effected at 

 Jibuti with the chronometer of Tli/' Eljiliinstoiie of the Indian Navy, and on 

 4th May, yet another with the chronometer of the Post Office at Mombasa. \t 

 Entebbe, thanks to steps previously taken, it was found possible on i2th May 

 to make a fresh comparison liy wire with Mombasa, so that by means of these 

 two comparisons was obtained a first diurnal correction of the chi'onometers to 

 be used in the subsequent calculations. 



The elements of comparison appear in the record of the pocket chrono- 

 meters included in the present Report. From it we find that at Mombasa, on 

 4th July, at noon, local time, there were the following absolute corrections on 

 Greenwich mean time : 



Ki = + 3" 16" 

 K., = + 3 26 



+ 3 



34^-9 

 9 -0 



10 -5 



£09 



