A pernicious climate, warm and damp lands, which engender fevers, barbarous natives, some of whom are still cannibals, a permanent state of war between tribes, the slave-traders' suspicion of every stranger who seeks to discover the secrets of their infamous commerce; such are the difficulties to surmount, the dangers to overcome in this province of Angola, one of the most dangerous of equatorial Africa.
Tuckey, in 1816, had ascended the Congo beyond the Yellala Falls; but over an extent of two hundred miles at the most.

This simple halting-place could not give a definite knowledge of the country, and nevertheless, it had caused the death of the greater part of the savants and officers who composed the expedition.

Thirty-seven years later, Dr.Livingstone had advanced from the Cape of Good Hope as far as the upper Zambesi.

Thence, in the month of November, with a hardihood which has never been surpassed, he traversed Africa from the south to the northwest, cleared the Coango, one of the branches of the Congo, and on the 31st of May, 1854, arrived at St.Paul de Loanda.

It was the first view in the unknown of the great Portuguese Colony.
Eighteen years after, two daring discoverers crossed Africa from the east to the west, and arrived, one south, the other north, of Angola, after unheard-of difficulties.
The first, according to the date, was a lieutenant in the English navy, Verney-Howet Cameron.