MFUMBIRO, or KIRUNGA  , general names for a chain of volcanic mountains extending across the Central African, or Albertine, rift-valley immediately north of Lake Kivu . The range, the result probably of recent geological changes, completely blocks the valley at this point, forming a divide between the rivers flowing north to the Nile and the waters of Lake Kivu, connected through Tanganyika with the Congo system . The chain consists of two groups of mountains, surrounded by a vast lava field . The western group lies directly north of Lake Kivu, and contains two active volcanoes, Kirunga-cha-gongo, the nearest to the lake (11,194 ft. high), and Kirunga-namlagira(9711 ft.), some ro m. further north . The eastern group contains several higher peaks—some rising to needle-like points, others being truncated cones . The most lofty, Karissimbi (14,683 ft.), lies in 29° 27' 20" E., 1° 30' 20" S . Mikeno, a few miles north and west of Karissimbi, is 14,385 ft. high . The most easterly of the peaks, Muhavuru (13,562 ft.), in 29° 40' 30" E., 1° 23' S., is an isolated sugarloaf-shaped mass with a crater filled with water on its summit . This is the mountain to which the names Mfumbiro and Kirunga were originally applied . Some 6 m. west and a little north of Muhavuru is Sabyino (Sabinjo), 11,881 ft. high . The eastern peaks are snowclad for a part of the year . North of these high mountains is a district, extending towards Albert Edward Nyanza, containing hundreds of low peaks and extinct volcanoes .

It is to this region that the name Umfumbira or Mfumbiro is said properly to belong . Mfumbiro, i.e . Muhavuru, was first seen by a

white man in 1861, J . H . Speke, in his journey to discover the source of the Nile, obtaining a distant view of the cone, which was also seen by H . M . Stanley in 1876 . By its Baganda name of Mfumbiro (cook-house mountains) it figured on the maps somewhat east of its true position, first ascertained by Franz Stuhlmann in 1891 . In 1894 Count von Gotzen travelled through the volcanic region, and the range was subsequently explored by E . S . Grogan, Major St Hill Gibbons, Captain Herrmann, Dr R . Kandt and others, the principal heights being determined in 1903 .

In 1907-1908 the range was geologically and topographically examined by the

duke of Mecklenberg's expedition . By the Anglo-German agreement of the 1st of July 1890 " Mount Mfumbiro " was included in the British sphere in East Africa . See Captain Herrmann, " Vulkangebiet des zentralafrikanischen Grabens," in Mitteil. v . Forsch. u . Gelehrten a. d. deutschen Schutzgebieten, vol. xvii . (Berlin, 1904), and Adolf Friedrich, duke of Mecklenburg, Ins Innerste Afrika (Leipzig, 1909) ; both give maps .