J Erhardt

This is a comprehensive endeavour by the missionaries Krapf and Erhardt to depict large areas of East and Central Africa including the Great Lakes. From the information at their disposal it appeared that one huge lake lay at the centre of the area. Their representation of this lake, depicted in Map 2A, suggested a slug, hence the popular name of the map.

The map itself has never been published but is in the possession of the Royal Geographical Society, London. The Map Curator of the R.G.S. has kindly provided a photo copy of the relevant portion of the map, exhibited as map 2B, stating that this is the best that can be made.

To bring out the salient points, the Survey and Mapping Division of the Ministry of Lands, Housing and Urban Development undertook an enlargement (times 2) which accurately reproduces the features which are of particular concern to this story, but omits many others.

Ngorongoro and the Serengeti do not yet appear, but the whole of the country from north of Lake Natron to south of the Pare Mountains is assigned to ILMASAI.

Oldonyo Lengai is shown as "Snow Mt. (rain Mt.) Gods Mt.". "Kignea" and "Kilimanjaro" are also shown as snow mountains. The reason for including Lengai in this category is because mineral deposits which appear on the upper slopes of the volcano show upwith such brilliant whiteness as to give to the early observers the impression of snow.

It is of interest to note that the trade in soda from Lake Natron (though not named as such) was in existance at the time: "From where the Magad [soda] is bought."

Another point of interest depicted in the extreme north east corner of the map is a reference to a stream flowing into "the Ukerewa" I.e. Lake Victoria. It is noted that "This water tho' sweet is said to turn peoples teeth yellow". This is probably the first recorded reference to the fact, particularly noticeable around Mount Meru, that a high flourine [sic] content in the drinking water, does cause a brown stain to the teeth which cannot be removed.

The Map was presented to the Royal Geographical Society on 10th November 1855 by the missionary Erhardt. Its official title is as follows:

"Sketch of a Map from 1 & deg;N. to 15 & deg;S. Latitude and from 23 & deg; to 43 & deg;E. Longitude delineating the probably position and extent of the Sea of Uniamesi as being the continuation of the Lake Niasa and exhibiting the numerous heathen-tribes situated to the East and West of that great Inland-sea together with the Caravan routes leading to it and into the interior in general. In true accordance with the information received from natives - Representatives of various inland tribes - and Mahomidan inland traders. By the Revd. Messrs. Erhardt and F. Rebmann Missionaries of the Church Miss. Society in East Africa Kisaludini March 14 1855."

A paper published in German - J. Erhardt's Memoire Zur Erlauterung Der Von Ihm Und J. Rebmann, Zusammengestellten Karte Von Ost- Und Central-Afrika , (S.Tafel 1.) - gives further details of the country concerned. It is the first attempt at assessing the geographic position of the main geographic features of eastern Africa - Kilimanjaro, Lengai, Lake Victoria etc. by the length and direction of each days march undertaken by the trading caravans.