The universal geography : earth and its inhabitants

LAKE XYASSA. 285of the Zambese delta. The Ligonya, whicb reaches the coast midway betweenQuelimane and Mozambique, as well as the Lurio (Lu-Eio), which waters theLomwe territory, discharging into a bay about 120 miles north of the capital, havealso their farthest hcadstrcams in the Namuli uplands. Numerous other lesscopious watercourses rising in the advanced spurs of the same hiUy districts havetheir estuaries on the seaboard between the liurio and Rovuma mouths.The Rovuma (Ro-Vuina, Ru-Vuma), which forms the northern frontier lino ofMozambique, is a considerable stream whose basin comjiriscs nearl}' the wholeeastern drainage of the mountains skirling the cast side of Nyassa. Its farthestaffluents even rise to the south of the lake, their united waters forming the Liendaor Lujenda (Lu-Jenda), which for the length of its course must be regarded as themain upper branch of the Rovuma. Till recently it was even supposed to haveits origin some 60 miles farther south in the Milangi hills, and that it consequentlytraversed Lake Kilwa, the Shirwa of English writers, discovered by Livingstone in1859. But this lake is now known to be an independent reservoir without anypresent outflow, although it apparently belongs geologically to the same depressionas the Lujenda Valley, with which at some former period it was probablyconnected.Lake Kii.wa.The sillconfining the lacustrine basin on the north varies in height from about14 to 30 feet at the utmost. This low ridge also lies considerably more than amile from the northern extremity of the lake, and is clothed from one end to theother with large timber, showing that this tract has ceased to be flooded for a periodof at least a hundred years. Nevertheless it is quite possible that in exceptionallywet seasons the level of Lake KUwa may rise sufficiently to fiU the sluggish marshychannels at its north-west extremity, and thus effect a communication northwardswith the sources of the Lujenda, bj- skirting the western extremity of the oldmargin of the lake, where the ground is almost perfectly level. According to thestatements of the oldest inhabitants, such communication in point of fact frequentlytook place before the present century ; but the level of Lake Kilwa has neverceased to fall lower and lower ever since thai time. Hence this basin has now nooutflow, the inflow being balanced by evaporation, while its waters, formerly freshand potable, have now become quite saline.In its present condition the lake has an almost perfectly rectangular form,being about 86 miles long, with a mean breadth of18 miles and a superficial areaapproximately estimated at 720 square miles. Rut it is \ery shallow, especiallyon the east side, which is fordable for a loug distance from the shore. The deepestpart of the basin lies on the west side, under the escarpments of Mount Chikala,which rises precipitously to a height of from 2,000 to 2,600 feet above the lacustrinelevel, which itself stands nearly 2,000 feet above the sea. The two rockyislands of Kisi and Ivitongwe .serve to indicate the direction of a sub-lacustrineridge which traverses the basin from north-east to south-west. This ridge will