For almost the whole of the nineteeth century many maps of Africa showed a massive range, known as the Mountains of Kong, running horizontally nearly 4000 miles across the middle of the continent along the 10th parallel. Only in 1889 was it’s existence declared wholly fictitious by a French explorer who had just returned from tracing the path of the Niger River.
It seems that the mountains first appeared on a map published in 1798 by the experienced and well-regarded London map maker James Rennell. The name Kong comes from a small town that does exists on the Ivory Coast but the mountains seem to have materialised from vague traveller reports compounded by a desire to add some detail to a huge blank in the middle of a vast region.
This is a brilliant example of the truism that nature hates a vacuum and so of course do we. Even where there are empty spaces with no dots we will if necessary invent some to join up. It’s uncertainty that fills us with terror.