The inundation I have explained in the note on the climate as owing to the sponges being supersaturated in the greater rains, when the sun returns from his greatest southern declination, the pores are then all enlarged, and the water of inundation flows in great volume even after the rains have entirely ceased. Something has probably to be learned from the rainfall at or beyond the equator, as the sun pursues his way north beyond my beat, but the process I have named accounts undoubtedly for the inundations of the Congo and Zambesi. The most acute of the ancients ascribed the inundation with Strabo to summer rains in the south; others to snows melting on the Mountains of the Moon; others to the northern wind--the Etesian breezes blowing directly against the mouth of the river and its current: others, with less reason, ascribed the inundation to its having its source in the ocean: Herodotus and Pliny to evaporation following the course of the sun. _1st September, 1868._--Two men come from Casembe--I am reported killed. The miningo-tree distils water, which falls in large drops. The Luapula seen when the smoke clears off. Fifty of Syde bin Omar's people died of small-pox in Usafa. _Mem._ Vaccine virus. We leave on the 25th, east bank of Moisi River, and cross the Luongo on the 28th, the Lofubu on the 1st October, and the Kalongosi on the 7th. [Dr. Livingstone seems to have been unable to find opportunity to make daily entries at this period. All was turmoil and panic, and his life appears to have been in imminent danger. Briefly we see that on his way back from the Lake he found that his Arab associates of the last few months had taken up Casembe's cause against the devastating hordes of Mazitu, who had swept down on these parts, and had repulsed them. But now a fresh complication arose! Casembe and Chikumbi became alarmed lest the Arabs, feeling their own power, should turn upon them and possess the whole country, so they joined forces and stormed Kombokombo, one of the leading Arabs, and with what success we shall see. It is a fair specimen of the unaccountable complications which dog the steps of the traveller, where war is afoot, and render life a misery. He writes as follows on the 5th October:--] I was detained in the Imbozhwa country much longer than I relished. The inroad of the Mazitu, of which Casembe had just heard when we reached the Mofwe, was the first cause of delay: he had at once sent off men to verify the report, and requested me to remain till his messengers should return. This foray produced a state of lawlessness in the country, which was the main reason of our further detention.