Petherick’s Expedition to Gondokoro. 261 
"_ “These circumstances being taken into account, together with the fact 
of Mr. Petherick’s services being now available, who, beyond any other 
h 
=a unemployed for securing those services to the advancement of 
having declined to send out this additional expedition, the President and 
Council make their appeal to the liberality of individual Fellows of the 
Society and to that of the Public. 
Although only £1000, or half of the sum called for, was 
Taised, Mr. Petherick set out in April, 1861. Letters have been 
issued by the Honorary Secretary of the Society, F. Galton, Esq. : 
check your results with known latitudes; also to practise observing eclip- 
8 and occultations under the same circumstances. 
“2. As ral rule, observations should be made at marked points, 
such as the confluence of rivers, prominent hills, and native towns, rather 
than at mere encampment. 3 : 
“3, Reliable latitudes of different places on the White Nile between 
Khartum and Gondokoro, and on your further line of travel. The lati- 
ed, and the meridian altitudes of at 
least six stars; three north and three south should there be observed. 
“4, Longitud th eedingly simple methods of the eclipses of 
Sia te ae to be made at Gondokoro 
Parallel of b valuable. 
eg the Bahr el Ghazal would be very bys ie 
_ temperature of boiling water :—Cai Assoun ; Junction 
= Atbara ; Khartum ; the capital of the S 
. 
and to be carefu reserved, with the view of determining any changes 
- their index st They are also to be comp red with those of Captain 
: in the event of the hoped-for meeting taking place. between you 
and that gentleman. | 
56. The three boiling-point thermometers to be occasionally compared, 
| 
