THE DESICCATION OF AFRICA 
147 
that the Shire river sometimes flows slowly back into Lake 
Nyasa in exceptionally dry periods. 
On the precipitous shores of deep bays such as Monkey 
Bay, Mkata Bay, and Karonga, the former water levels are very 
noticeable. 
In 1895 the steamer Queen Victoria, 150 tons, was built 
and launched at a certain spot on the Shire river (below Lake 
Malombe), where in 1908 It was only possible to force through 
the vegetation a boat drawing three or four feet. I took note 
of the former water level, which was over ten feet above the 
then water level. The decrease of water continued to the 
extent that in 1910 the shallow- draught stem- wheelers with 
great difficulty managed to reach Port Herald at extreme 
south end of British Nyasaland. It has since been found 
absolutely necessary to extend the Nyasaland Railway south- 
wards into Portuguese territory some forty miles. 
Lake Shirwa (south-east end of Nyasa, near Zomba) is 
rapidly becoming a papyrus and reed-covered marsh. The 
surrounding country and flats towards Nyasa invite the con- 
clusion that the Shirwa was an arm of Nyasa at no very 
remote date. 
The Elephant Marsh, Chiromo, on the lower Shire, is no longer 
a marsh. My first visit was in 1908. Since then I have traversed 
it in many directions, and have camped in it for weeks on end 
away down towards the Zambesi and the Portuguese border. 
During the rains I have certainly had to circumvent stretches 
of water held in depressions by the kaolin sub-soil, but which 
rapidly evaporates when rains cease. During a long dry season 
one must depend on water holes in certain places. Some of 
these appear to be getting deeper and deeper every year by 
native efforts to reach the receding permanent water from the 
sloping hole down which steps were cut. With the records of 
Livingstone and Mackenzie to refer to on the spot, it was difficult 
to realise that so much and such expanses of water as they 
described had drained off and evaporated in forty years. The 
Sangasi, a tributary which enters the Shire at Chiromo, which 
must once have had a considerable volume of water, judging 
from old sand levels, 1905-1910, is now, except for a few days 
during the rains, a river of sand with well-defined banks which 
