1901.] Magnetic Observations in Egypt, 1893—1901. 21 







XJah 



N 



Long. E. 



Declination. 

 1863-64. 







12° 



42' 



34° 



25' 



. 9 o 



10' 







12 



8 



34 



15 



20 



01 







12 



8 



34 



10 



6 



30 







11 



54 



34 



3 



12 



05 



Gule 





11 



43 



33 



57 



8 



40 



Also Captain A. W. Peel gives the West Declination at Khartum, 

 as 8° 30' in October, 1851, and Lieut. Watson, E.E., gives 7° 30' West, 

 for that of Rejaf (lat. 4° 40' ±), on 15th December, 1874. 



The only other observation it has been possible to find in the books 

 of travel, &c, available in Cairo, is a value of 7° 30' W. for the decli- 

 nation at Gondokoro on March 20, 1861,* which with 6° 20' for the 

 present values gives - 2' per annum. 



Unfortunately the first rains were already threatening at Lado and 

 Gondokoro, and the sky was usually too cloudy to admit of satis- 

 factory observations for azimuth, Hellet el Nuer and El Kenisa were 

 therefore the only two places where the declination could be deter- 

 mined on the Bahr el Jebel. Eussegger also gives for El Obeid 

 declination 8° 30' west and dip 18° for April, 1837, but neither of 

 these can be utilised, being too far from the Nile. 



The instruments used were Kew-pattern Magnetometer, No. 87, by 

 Elliott, and a Dip Circle, No. 131, by Dover. 



* Penej, ' Bull. Soc. Geog. Paris,' 1863. 



