frightful death-toll. Only the strongest ever reach the slave-markets,
and it has been calculated that at least 500,000 lives are annually
sacrificed during transit. Indirectly the slave-owner has to pay for
these. When slaves were taken in war, they cost nothing to transport;
but when Mohammedan conquests ceased, the supply ceased with it, for
Mohammedans are not allowed by the Koran to make slaves of men of their
own creed, though they do sometimes infringe this rule.

It is generally supposed that the slave trade originated in the fact
that in certain parts of Central Africa there are no horses or beasts
of burden, as owing to the existence of the tetse-fly no animal can
live. Consequently ivory and everything else has to be carried on the
heads of porters. These porters were engaged by the Arab ivory dealers
in the interior, and marched in large gangs to the seaports. Having
reached their destination, and given up their loads, the question of
transport back to their villages would arise. The Arab traders found
that it would suit their purpose best to sell the porters as slaves.
Who was to know whether or not they were taken in battle? In Mohammedan
countries, so long as plenty of backsheesh is forthcoming, those in
authority ask few questions. Soon the sale of slaves became more
profitable than the ivory trade, which possibly had originated it, and
so the one was substituted for the other, the authorities not only
winking at it, but encouraging it as a source of large revenues to
them. At one time a large number of so-called Christians were engaged
in this unholy traffic, but the scandal became so great that European
public opinion would not tolerate it, and so they had to sell their
stations to Mohammedan Arabs, who if possible were even more cruel and
relentless in the way they conducted the trade. Merchant princes arose
among them, and they carried on their business with a thoroughness and
a system worthy of a better cause. Soldiers were trained, and large
armies kept for no other purpose than that of collecting slaves.
Peaceful villages were surrounded, night attacks were made, whole
tribes were marched off to the slave markets, the road being lined by
grinning skulls to show the way in which the victims suffered _en
route_.

"Not for this
Was common clay ta'en from the common earth,
Moulded by God, and tempered with the tears
Of angels, to the perfect shape of man!"