Proceedings of Learned Societies. 155 



jaro mountain was observed from various points. It is said to rise 

 very gradually from the surrounding country. The summit, from 

 one point of view, presents the appearance of a great dome, and 

 from another that of a cone with a small plain on the top. Two 

 other high peaks, belonging to the same groiip of mountains as Ki- 

 limandjaro, have been observed. One of these, at a distance of 

 about 15 miles K., appears to have a height of 17,000 feet, and the 

 other, apparently 60 miles ~W., seems to be 18,000 feet in height. 

 The explored peak is decidedly volcanic ; and Mr. Thornton con- 

 siders that it may be merely the remaining peak of a vast volcano, 

 by far the larger part of which has subsided to a lower level. The 

 central axis of the mountains appears to run from IST.E. to S.W. ; 

 and it is thought probable that, when this is reached, granite will 

 be found. 



Sir Henry Rawlinson read a letter from Colonel Pelley, H.B.M. 

 Consid at Zanzibar, stating that Baron von Decken intended to 

 continue his explorations, and that the river Ozee, which flows into 

 the Indian Ocean, not far south of the Equator, and is supposed to 

 rise in the northern prolongation of the Kilimandjaro range, was be- 

 ginning to attract attention. 



Ascent of the Ogun (the Abbeokuta Biver), by Capts. Burton 

 and Bedingfield and Dr. Eales.— Captain Burton recorded his ascent 

 of this river, and his opinion that the whole country, from the 

 Niger to the Volta, is well suited for the growth of cotton. He 

 thinks that the population of the district has been under estimated, 

 and that, instead of being called 100,000, it ought to be 150,000. 

 He rather scoffs at the King of Dahomey's Amazons, and thinks 

 that their number is less than previous travellers have stated. 



Captain Strickland made some remarks with regard to the Ab- 

 beokutans. He said that they displayed great aptitude for trading, 

 and might be called the Jews of Africa. Abbeokutans taken as 

 slaves to Brazil, soon purchase their freedom, and also that of others 

 who are brought to that country as part of cargoes of slaves. 

 They are intelligent, and appear to preserve the remains of an 

 ancient civilization. 



THE ROYAL SOCIETY.— January 30. 



Absorption and Radiation op Heat by Gaseous Matters. — Dr. 

 Tyndall described the results of his continued investigations on the 

 absorption of heat by gases and vapours. The absorption of radiant 

 heat by atmospheric ah" in a short tube, and at a tension of thirty 

 inches, being taken as 1 ; Chlorine would be 36 ; Hydrochloric 

 acid, 62 ; Carbonic acid, 90 ; Sulphuretted hydrogen, 390 ; Olefiant 

 gas, 970; Ammonia, 1195. The absorption of radiant heat by 

 vapours was also found to be very considerable, and even small 

 quantities of perfumes, when diffused through common air, increase 

 its power of arresting heat to an extraordinary degree ; thus the 

 absoptive power of ah- charged with the perfume of patchouli is 30 

 times greater than that of pure air ; lavender increases the power 



